bluuebunny/crossref_metadata_2025 huggingface dataset:
INVISIBLE FLORAL LARCENIES: MICROBIAL COMMUNITIES DEGRADE FLORAL NECTAR OF BUMBLE BEE‐POLLINATED PLANTS
Authors: Herrera Carlos M. , García Isabel M. , Pérez Ricardo
Published: September 2008

The ecology of nectarivorous microbial communities remains virtually unknown, which precludes elucidating whether these organisms play some role in plant–pollinator mutualisms beyond minor commensalism. We simultaneously assessed microbial abundance and nectar composition at the individual nectary level in flowers of three southern Spanish bumble bee‐pollinated plants (Helleborus foetidus, Aquilegia vulgaris, and Aquilegia pyrenaica cazorlensis). Yeasts were frequent and abundant in nectar of all species, and variation in yeast density was correlated with drastic changes in nectar sugar concentration and composition. Yeast communities built up in nectar from early to late floral stages, at which time all nectaries contained yeasts, often at densities between 104 and 105 cells/mm3. Total sugar concentration and percentage sucrose declined, and percentage fructose increased, with increasing density of yeast cells in nectar. Among‐nectary variation in microbial density accounted for 65% (H. foetidus and A. vulgaris) and 35% (A. p. cazorlensis) of intraspecific variance in nectar sugar composition, and 60% (H. foetidus) and 38% (A. vulgaris) of variance in nectar concentration. Our results provide compelling evidence that nectar microbial communities can have detrimental effects on plants and/or pollinators via extensive nectar degradation and also call for a more careful interpretation of nectar traits in the future, if uncontrolled for yeasts.
Persistent vaginal hemorrhage caused by vaginal vascular ectasia in a dog
Authors: Gower Jessica A. , Schoeniger Sandra J. , Gregory Susan P.
Published: September 2008

Case Description—A 6-year-old 36.5-kg (80.3-lb) spayed female Labrador Retriever was evaluated because of an 11-month history of vaginal bleeding. Previous radiographic, endoscopic, and surgical interventions had failed to detect an underlying cause for the bleeding. The dog was examined on an emergency basis because of severe anemia after the bleeding increased in severity.

Clinical Findings—Bleeding was severe, and results of vaginoscopy and radiography (after administration of a contrast agent) did not confirm the cause of the hemorrhage. An exploratory episiotomy revealed multiple bleeding vascular abnormalities within the vaginal mucosa cranial to the external urethral orifice, which were suggestive of vascular ectasia.

Treatment and Outcome—A total vaginectomy was performed via a ventral midline incision and a pubic symphysiotomy. Macroscopic and microscopic examination of excised vaginal tissues confirmed changes compatible with vascular ectasia. The dog made an uneventful recovery with no further vulval bleeding until 19 months after surgery, at which time vulval bleeding recurred. Further investigation and treatment were declined by the owner.

Clinical Relevance—Vascular ectasia may be a cause of chronic vaginal hemorrhage and life-threatening anemia in dogs. In the dog of this report, the diagnosis was made on the basis of direct observation during exploratory episiotomy and histopathologic findings. To manage the condition, total vaginectomy was performed; however, despite radical surgery, bleeding recurred.
Review of Controlled Psychotherapy Treatment Trials for Binge Eating Disorder
Authors: Krysanski Valerie L. , Ferraro F. Richard
Published: September 2008

This paper reviews investigations of psychotherapy outcome studies for binge eating disorder, which has recently been intensively studied as several researchers have undertaken the task of delineating which treatment options are the most effective. Several randomized, controlled clinical trials have provided important findings. A current debate concerns what the initial course of treatment should be, reducing binge eating patterns or reducing weight. Several limitations to this literature are mentioned, including the dearth of studies investigating treatment for men and boys with binge eating disorder.
Development of an IQ Test for New Zealand Adults
Authors: Hattie John , Fletcher Richard
Published: September 2008

In 2003 and 2004 a television network in New Zealand showed a syndicated program called Test the Nation: The New Zealand IQ Test. This paper demonstrates how the IQ test was devised using item response theory, and evaluates the properties of the test using data from the TV program participants.
On use of Student Samples for Scale Construction
Authors: Pernice Regina E. , Ommundsen Reidar , Van Der Veer Kees , Larsen Knud
Published: September 2008

This research note responds to the question of whether a convenience sample of undergraduate students may be successfully utilized in concept development and in scale construction, and in what way the results are comparable to the findings of a representative national sample. The results of a Mokken analysis in both samples support the hypothesis that convenience samples have utility in concept development and in developing measures that can also be used in representative samples.
Magnitude of Relationship between Burnout and Absenteeism: A Preliminary Study
Authors: Gil-Monte Pedro R.
Published: September 2008

This study examined the influence of guilt related to a negative attitude toward patients and its relation with burnout and absenteeism. The sample consisted of 717 nursing professionals. Depersonalization was evaluated by the Maslach Burnout Inventory and Guilt was evaluated by one item. To estimate Absenteeism, participants were asked about the number of workdays they had missed in the past year. Hierarchical multiple regression analyses make it possible to conclude that guilt explains work absenteeism, and the interaction between depersonalization and guilt (Incr. R2 = .008, p<.05) indicates significant differences in the number of work days missed in the last year. Conclusions are limited, as these effects are quite weak: all variables together only explain about 4% of the shared variance in absenteeism. Researchers might assess whether feelings of guilt help explain the relationship between burnout and symptoms such as absenteeism.
Relationships between Personality and Time-Related Strains
Authors: Van Emmerik Ij. Hetty
Published: September 2008

Using data from a Dutch representative national sample of 1,249 respondents (40% women and 60% men), all engaged in paid labor, the relationships between Big Five personality traits and time-related strains (i.e., Time Pressure and Work Pressure) were examined. Hierarchical regression analyses showed that Emotional Stability was negatively and Openness to Experience was positively related to both types of time-related strains. Emotional Stability and Agreeableness were more strongly negatively associated with generalized Time Pressure than with context-specific Work Pressure. This supports the Strong versus Weak Situations Hypothesis of Mischel.
Cognitive Demands of Error Processing
Authors: Koehn J. D. , Dickinson J. , Goodman D.
Published: September 2008

This study used a dual-task methodology to assess attention demands associated with error processing during an anticipation-timing task. A difference was predicted in attention demands during feedback on trials with correct responses and errors. This was addressed by requiring participants to respond to a probe reaction-time stimulus after augmented feedback presentation. 16 participants (8 men, 8 women) completed two phases, the reaction time task only and the anticipation-timing task with the probe RT task. False feedback indicating error and a financial reward manipulation were used to increase relevance of errors. Data supported the hypothesis that error processing is associated with higher cognitive demands than processing feedback denoting a correct response. Individuals responded with quicker probe reaction times during presentation of feedback on correct trials than on error trials. These results are discussed with respect to the cognitive processes which might occur during error processing and their role in motor learning.
A Comparison of Two Lists Providing Emotional Norms for English Words (ANEW and the DAL)
Authors: Whissell Cynthia
Published: September 2008

Although different in terms of purpose, word-selection procedures, and rating scales, both the ANEW ( n = 1034) and DAL ( n = 8742) lists, which have 633 words in common, provide normative emotional ratings for English words. This research compared the lists and cross-validated the two main lexical dimensions of affect. Parallel representatives of the two dimensions (Valence and Pleasantness, Arousal and Activation) were correlated across lists ( rs = .86, .63). In tune with their separate purposes, the ANEW list, which was designed to describe emotional words, included more rare words, while the DAL, which was designed for natural language applications, included more common ones. The Valence-Activation scatterplot for ANEW was C-shaped and included fewer Arousing words of medium Valence, such as “awake,” “debate,” and “proves,” while the DAL included fewer less common words descriptive of emotion such as “maniac,” “corrupt,” and “lavish.” In view of these differences, list similarities strongly support the generalizability of the two main lexical dimensions of affect.
Possible Role of Posttraumatic Stress Disorder in Suicide Terrorists: An Hypothesis
Authors: Lester David
Published: September 2008

Recent reports by journalists of suicidal terrorists suggest that exposure to recent violence in traumatic situations, combined with childhood exposure to violence, may lead to posttraumatic stress disorder, which in turn may result in suicidal violence.
Influence of Emotional Content and Perceived Relevance on Spread of Urban Legends: A Pilot Study
Authors: Cotter Ellen M.
Published: September 2008

This study examined factors thought to be associated with the spread of urban legends. 62 participants (84% female, 65% white, M age = 22 yr.) read 15 urban legends, 3 of which had a stated local component, and rated various characteristics of each legend, including how scary it was, how believable it was, and how likely the participants would be to tell it to someone else. As predicted, both a high fear rating and a high believability rating were positively correlated with the reported intent to tell (p60 = .41, p<.0001 and p60 = .67, p<.02, respectively). There was also a significant positive correlation between familiarity and intent to tell (p60 = .22, p< .0001); however, presence of a local connection was not strongly correlated with intent to tell. It is possible that the local stories were less believable because they all involved ghosts.
Assessing Return on Investment of Freeway Safety Service Patrol Programs
Authors: Dougald Lance E. , Demetsky Michael J.
Published: September 2008

Safety service patrol (SSP) programs are widely used to help mitigate the effects of nonrecurring congestion and have become an increasingly vital element of incident management programs. In recent years, some state departments of transportation have initiated return-on-investment evaluations of their SSP programs. The purpose of this project was to use Virginia data to develop methods to evaluate and quantify the benefits of SSP programs; this involved developing a methodology to determine incident durations with and without SSPs for the Northern Virginia region and applying the results to a model to quantify the benefits associated with reductions in motorist delay, fuel consumption, and emissions attributable to SSP operations. To verify the general applicability of the methodology, the evaluation procedure was applied to the Hampton Roads, Virginia, SSP. The results showed that incident duration reductions attributable to SSP operations in these two areas resulted in benefit–cost ratios of 5.4:1 and 4.7:1, respectively. The methodology developed can be used by other agencies that have the means to collect and archive incident duration and location data. The amount of effort involved in applying the methodology is dependent on the type of data collected by the SSP and the state police and the level of integration of SSPs and computer-aided-dispatch databases in those regions.
Freeway Incidents in the United States, United Kingdom, and Attica Tollway, Greece
Authors: Prevedouros P. , Halkias B. , Papandreou K. , Kopelias P.
Published: September 2008

A summary of real-world incident statistics is presented from various freeways, and statistics from the Attica Tollway, in Greece, are simultaneously compared with incident data from U.S. and U.K. freeways. Detailed statistics are available from the Attica Tollway; statistics for U.S. and U.K. freeways were compiled from the available literature. Attica Tollway capacity under incident conditions is compared with estimates from the Highway Capacity Manual 2000. Interestingly, the incident capacity estimates by freeway number of lanes available and number of lanes closed because of an incident are practically identical for the Attica Tollway and U.S. freeways. This finding agrees with conclusions by others that similarly configured (standard) freeways produce similar incident profiles. The implication is that incident behavior could be predictable, but detailed analytical models are lacking. To this end, models are developed to explain the correlations between incident duration or queue length and a variety of independent variables such as number of crashed vehicles, number of responding vehicles, response times, number of lanes at the incident location, and various other temporal factors.
Simple Approach to Estimating Changes in Toll Plaza Delays
Authors: Ozmen-Ertekin Dilruba , Ozbay Kaan , Mudigonda Sandeep , Cochran Anne M.
Published: September 2008

Toll plazas are important components of the road infrastructure, especially on urban highways. They can have adverse capacity and safety impacts on traffic. However, the plazas serve an important purpose, namely, revenue generation for highway agencies. Various traffic management and electronic toll collection strategies, including regular and high-speed E-ZPass and time-of-day pricing, are also implemented as part of toll plaza operations to change traffic supply and demand characteristics and improve networkwide level of service. In recent years, because of the increasing need to better assess the impact of toll plazas combined with these various traffic management strategies, customized or off-the-shelf microsimulation and macrosimulation models of toll plazas have been developed. This study reviews the literature on both approaches. Then a customized microscopic toll plaza model developed as an integrated part of PARAMICS microsimulation is compared with a relatively simple macroscopic model. This kind of macroscopic model, which can estimate toll plaza delays, is needed because it is extremely difficult and expensive to calibrate and implement microsimulation models when projects have severe budget and time constraints. Several New Jersey Turnpike toll plazas that were well validated and calibrated are used in the comparison. A sensitivity analysis is conducted with various other toll plazas to ensure the validity of the macroscopic model, especially for cases in which demand is reduced because of a real-time traffic management strategy. Results indicate that the macroscopic method is comparable (within average error 2.6% to 6.4%) with the PARAMICS model when sufficient care is taken in selecting macroscopic and microscopic model parameters consistently.
Two-Phase Model of Ramp Closure for Incident Management
Authors: Boyles Stephen , Karoonsoontawong Ampol , Fajardo David , Waller S. Travis
Published: September 2008

Temporary on-ramp closure has been proposed as a strategy to reduce the impact of severe incidents on freeway facilities; however, to date no rigorous procedure has been made available to provide guidance on how such a technique should best be used. In particular, one must decide which ramps to close and for how long. A two-phase approach is proposed to answer these questions. The first phase is macroscopic in nature and predicts how motorists will reroute in response to any ramp closure and recommends which ramps should be closed. The second phase uses microsimulation to study the vicinity of the incident in greater detail, more fully accounting for dynamic traffic phenomena and attempting to answer the question of how long these ramps should be closed. From a computational standpoint, the first phase is designed to run as quickly as possible to allow the ramp closure policy to be enacted as the second phase begins, since the results of the second phase are not needed until later. This procedure is demonstrated by using a fictitious incident in the El Paso region of Texas.
Developing Microscopic Toll Plaza and Toll Road Corridor Model with PARAMICS
Authors: Nezamuddin N. , Al-Deek Haitham
Published: September 2008

Many simulation models are available to study transportation system elements such as freeways and intersections. However, most of these simulation models do not come with a built-in toll plaza model readily available. Many researchers have independently developed toll plaza models, but they can model only an isolated plaza without the corresponding road network. Toll plaza models based on queuing theory do not take into account headway, gap acceptance, or intervehicle interactions to follow a lead car or to perform lane-changing maneuvers. For instance, if a vehicle is traveling in the leftmost lane and the rightmost toll lane has the shortest queue length, the queuing model will assign this vehicle to the rightmost lane, and the vehicle will make unrealistic maneuvers to reach the assigned toll lane instantly. If a microscopic network simulation model could be customized to model a toll plaza, not only would it simulate the vehicular movements realistically, but it could also model a toll road corridor integrated with the plaza, unlike the isolated toll plaza models. PARAMICS has many simulation tools, such as categories, vehicle type and restriction managers, next-lane allocation, and lane-choice rule, which have been customized to develop a corridor model containing the Holland East Plaza and sections of SR-408 in Orlando, Florida. This model was tested for various hypothetical scenarios, and the results obtained from these scenarios met expectations, which further attested to the validity of the model. This network model can simulate multiple toll plazas and can be integrated with other road networks (e.g., freeways and arterials).
Acid Cleaning Operation for Scale Attacked WaterWall Tubes of a High Pressure Boiler
Authors: Sohail M Azad , Mustafa A Ismail
Published: September 2008

In this paper, a two stage acid etching (TSAE) technique has been developed and investigated to cleanup hard deposits on internal surfaces of boiler water wall tubes (WWTs) for a natural circulation highpressure drum boiler(fossil) unit: TIME-206-COB (Russia) at Ghorasal Thermal Power Station(GTPS), Bangladesh. TSAE technique was carried out very carefully by using a mixed solution of ammonium hydrogen fluoride, hydrochloric acid in presence of inhibitor urotropine and cleaning agent OP- 10(Russia).To attained maximum cleaning efficiency at each end of the cleaning stage compressed air 6kgfcm-2 was passed through the boiler WWTs by bottom headers very carefully. The overall close observations on the (TSAE)) cleaning operation revealed that not less than 90% of impurities were removed. The cleaning mechanism and the passivation on cleaned surface of boiler WWTs by 2.0% NaNO3 in presence of 0.5% NH4OH (pH 10.5) at 55Â°C were found to be satisfactory. Close macrostructural examinations (by SEM) of the tube materials after the TSAE operations reveled there is no remarkable corrosion or micro creaks on boiler WWTs materials. Key words: Boiler, Deposit, Passivation, Boiler water wall tubes (WWTs), Acid etching.DOI = 10.3329/bjsir.v43i3.1148Bangladesh J. Sci. Ind. Res. 43(3), 333-344, 2008
Influence of Perceived Job Tension on Stress Reaction Among Hospital and University Workers in Nigeria
Authors: Omolayo Bunmi , Mokuolu Bola
Published: September 2008

The influence of perceived job tension on stress reaction among hospital and university workers in Nigeria was the focus of this study. 160 participants randomly selected from hospital and university settings were used for the study. The age of the participants ranges between 25 years and 50 years with a mean age of 35. Four hypotheses were tested and results shows that job stress is directly proportional to personal distress. Also, no significant difference was found in the job related tension between hospital and university workers. Result of this study shows that females have the same perception of work environment and they react to stress in the same manner. However, a significant difference exists in the level of stress between female and male university workers. Key words : 1. Job tension: The rigours and stress workers undergo on the job. 2. Stress reaction: It the way workers react to stress on the job. This could be positive or negative. 3. Stress: It is the unfavorable conditions that workers pass through in the course of discharging their job duties. 4. Stressors: These are conditions that bring about stress on the job. Â DOI = 10.3329/bjsir.v43i3.1150Bangladesh J. Sci. Ind. Res. 43(3), 353-358, 2008
Seasonal Prevalence and Intensity of Infestation by the Ectoparasites in Carps Relating to Physico-Chemical Parameters in Some Ponds of Mymensingh and Bogra Districts of Bangladesh
Authors: Bhuiyan Abdus Salam , Musa ASM
Published: September 2008

The research work was conducted to find out the seasonal prevalence and intensity of infestation of the ectoparasites of carps in some ponds of Mymensingh and Bogra districts of Bangladesh. Seven species of parasites viz. Trichodina domerguei, Trichodina reticulata, Chilodonella cyprini, Myxobohts koi, Dactylogiroides tripathi, D. extenswi and D. catlarius were found from 640 fry-fingerlings of silver carp, Hypophthalmicthys mohtrix (Valenciennes), grass carp, Ctenopharyngodon idella (Valenciennes), European carp, Cyprinns carpio (Linnaeus), small carp, Puntius gonionotus (Bleeker), katla, Catla catla (Hamilton), rui, Labeo rohita (Hamilton-Buchanan) and mrigal, Cirrhina mrigala (Hamilton- Buchanan) from different nurseries and rearing ponds of Mymensingh and Bogra districts of Bangladesh during June, 2004 to October, 2005. The overall percentage of infestations in two study areas was the highest (95%) in winter, moderate (48%) in summer and the lowest (34.8%) in the rainy season. The physicochemical parameters of water exerted more or less significant combined effect on the occurrence of parasites. Key words: Ectoparasites infestation, Carps, seasonal prevalence, Physicochemical parameters. Â Â DOI = 10.3329/bjsir.v43i3.1158Bangladesh J. Sci. Ind. Res. 43(3), 411-418, 2008
State controllability computation technique for linear time‐varying systems by using Taylor series approximation
Authors: Aksoy S.
Published: September 2008

This article presents a technique to determine the controllability Grammian matrix (CGM) for linear time‐varying systems by using truncated Taylor polynomial vector and the operational matrix of integration. An important property of this algorithm is that it starts by integrating the Lyapunov differential matrix equation in terms of the CGM. However, the algorithm does not use the mathematical integration processes actually, but uses the truncated Taylor polynomial vector and the operational matrix of integration. Thus, the problem is reduced to solving a linear set of algebraic equations with constant coefficients consisting of the Taylor polynomial constant coefficients of each of the CGM elements. Numerical results and error curves are given to illustrate the improvements achieved by the proposed algorithm. Copyright © 2008 John Wiley & Sons, Ltd.
Reversible Fluorescent On–Off Recording in a Highly Transparent Polymeric Material Utilizing Fluorescent Resonance Energy Transfer (FRET) Induced by Heat Treatment
Authors: Hirata Shuzo , Lee Kwang‐Sup , Watanabe Toshiyuki
Published: September 2008

One productive technique for ultrahigh resolution readout of tiny regions is the measurement of the fluorescence signal of materials. A transparent polymeric materials whose fluorescence quantum yield is changed and recorded by thermally controlling the aggregation of fluoran dyes and developers with long alkyl chains has been developed. The recording medium can be fabricated easily by casting or coating recording materials. Fluorescence is observed after annealing at 363 K for about twelve seconds and then cooling to room temperature (RT), and quenched by annealing at 423 K for a few seconds and then quenching to RT. Nondestructive readout by excitation light with a fluorescent contrast of above 10 is achieved using red, green, and blue fluorescent dyes. Fluorescence on–off switching is induced by fluorescent resonance energy transfer (FRET) from a fluorescent dye to a colored fluoran dye in the recording material. Fluorescence was uniformly quenched in the visible region after erasing. Since the recording materials allow the penetration of laser light due to the presence of crystals smaller than the wavelength range of visible light in both the emission and quenching states, nondestructive readout of the fluorescent signal by two‐photon absorption is accomplished. This work provides an important stepping‐stone for achieving rewritable‐type near‐field optical storage or multilayer recording.
The Cycloaddition Reaction Between α‐Bromo Vinylketenes and Imines: A Combined Experimental and Theoretical Study
Authors: Benfatti Fides , Bottoni Andrea , Cardillo Giuliana , Fabbroni Serena , Gentilucci Luca , Stenta Marco , Tolomelli Alessandra
Published: September 2008

The unusual behaviour of α‐bromo vinylketenes in the cycloaddition reactions with imines is described. This class of vinylketenes behaves as dienophiles in [2+2] reactions, but also displays an unusual diene reactivity in [4+2] reactions. Interestingly, the reactivity of α‐bromo vinylketenes can be modulated via a fine tuning of the substituents. For instance, a methyl group in the β‐position completely inhibits the [2+2] reaction and the [4+2] pathway is almost exclusively followed. A more hindered ketimine (instead of a simple imine) is enough to activate again the [2+2] mechanism. We have carried out a DFT theoretical investigation to rationalise these experimental observations. We have considered two pathways for the [2+2] reaction involving imine, that is, the endo and exo pathways. The former is favoured in the case of α‐bromo vinylketenes, while the latter is preferred for non‐substituted vinylketenes. Since the [4+2] cycloaddition becomes possible only when the s‐Z‐conformation of vinylketene is significantly populated, the presence of bromine substituents in this substrate is crucial in determining the [2+2] or [4+2] mechanisms. For unsubstituted vinylketenes, the barrier connecting the s‐E‐ to the s‐Z‐conformation is too high to be easily overcome. Thus, the s‐Z‐structure has a low population and the [2+2] mechanism is favoured. In the case of α‐bromo vinylketenes (especially the β‐methyl‐substituted ones), this barrier can be surmounted and the [4+2] mechanism becomes available.
Co‐occurrence of 4p16.3 deletions with both paternal and maternal duplications of 11p15: Modification of the Wolf–Hirschhorn syndrome phenotype by genetic alterations predicted to result in either a Beckwith–Wiedemann or Russell–Silver phenotype
Authors: South Sarah T. , Whitby Heidi , Maxwell Teresa , Aston Emily , Brothman Arthur R. , Carey John C.
Published: September 2008

Paternal duplications of chromosome region 11p15 can result in Beckwith–Weidemann syndrome (BWS), whereas maternal duplications of the same region on 11p15 can result in Russell–Silver syndrome (RSS). These two syndromes have numerous opposing phenotypes, especially with regards to growth parameters. The differences in the phenotype are proposed to be due to altered dosage of imprinted genes that control growth within this region of 11p15. Wolf–Hirschhorn syndrome (WHS) is due to deletions of a region in 4p16.3 and there is no known parent‐of‐origin effect for deletions of the WHS critical region, and no genes are known to be imprinted in this region. We report on three individuals with very similar unbalanced translocations resulting in a derivative chromosome 4 with both a deletion of 4p16.3 and a duplication of 11p15. Two of these individuals are family members with one inheriting the derivative 4 from her balanced mother and the other inheriting the derivative 4 from his balanced father. The third individual is unrelated and inherited his derivative 4 from his balanced father. While the findings of these individuals included some features of WHS and RSS or BWS, the phenotypes as an aggregate are distinct from these syndromes. The genomic and phenotypic characterization of these three individuals demonstrates how unbalanced translocations can result in the modification of chromosome duplication and deletion syndromes and identifies genomic architecture that may be responsible for mediating a recurrent translocation between 4p and 11p. © 2008 Wiley‐Liss, Inc.
Reply
Authors: Himmel Daniel , Trapp Nils , Krossing Ingo , Altmannshofer Sandra , Herz Verena , Eickerling Georg , Scherer Wolfgang
Published: September 2008

Die Kommentare von Krapp und Frenking werden gewürdigt, dennoch wird darauf verwiesen, dass eine detaillierte Beschreibung der Metall‐Ligand‐Bindung der AgI‐Acetylen‐Komplexe die Orbitalwechselwirkungen miteinbeziehen muss und eine rein elektrostatische Beschreibung, wie von Krapp und Frenking gewählt, zu stark vereinfachend ist.
Comments on “Homoleptical Silver(I) Acetylene Complexes”
Authors: Krapp Andreas , Frenking Gernot
Published: September 2008

In a recent publication, Krossing, Scherer, and co‐workers reported interesting experimental results for homoleptic AgIacetylene complexes. In this Correspondence the interpretation of the X‐ray analysis and the claim of “pseudo‐gas‐phase conditions” in the solid state are questioned.
Low‐temperature sol–gel transformation of methyl silicon precursors to silica‐based hybrid materials
Authors: Dhayal Veena , Bohra Rakesh , Nagar Meena , Kaushik Ajay , Mathur Sanjay , Barth Sven
Published: September 2008

Six new methyl silicon (IV) precursors of the type [MeSi{ONC(R)Ar}3] [when R = Me, Ar = 2‐C5H4N (1), 2‐C4H3O (2) or 2‐C4H3S (3); and when R = H, Ar = 2‐C5H4N (4), 2‐C4H3O (5) or 2‐C4H3S (6)] were prepared and structurally characterized by various spectroscopic techniques. Molecular weight measurements and FAB (Fast Atomic Bombardment) mass spectral studies indicated their monomeric nature. 1H and 13C{1H} NMR spectral studies suggested the oximate ligands to be monodentate in solution, which was confirmed by 29Si{1H} NMR signals in the region expected for tetra‐coordinated methylsilicon (IV) derivatives. Thermogravimetric analysis of 1 revealed the complex to be thermally labile, decomposing to a hybrid material of definite composition. Two representative compounds (2 and 4) were studied as single source molecular precursor for low‐temperature transformation to silica‐based hybrid materials using sol–gel technique. Formation of homogenous methyl‐bonded silica materials (MeSiO3/2) at low sintering temperature was observed. The thermogravimetric analysis of the methylsilica material indicated that silicon‐methyl bond is thermally stable up to a temperature of 400 °C. Reaction of 2 and Al(OPri)3 in equimolar ratio in anhydrous toluene yielded a brown‐colored viscous liquid of the composition [MeSi{ONC(CH3)C4H3O}3.Al(OPri)3]. Spectroscopic techniques 1H, 13C{1H}, 27Al{1H} and 29Si{1H} NMR spectra of the viscous product indicated the presence of tetracoordination around both silicon and aluminum atoms. On hydrolysis it yielded methylated aluminosilicate material with high specific surface area (464 m2/g). Scanning electron micrography confirmed a regular porous structure with porosity in the nanometric range. Copyright © 2008 John Wiley & Sons, Ltd.
Establishing survey and monitoring protocols for the assessment of conservation status of fish populations in river Special Areas of Conservation in the UK
Authors: Cowx I.G. , Harvey J.P. , Noble R.A. , Nunn A.D.
Published: September 2008

Under the EC Habitats Directive (92/43/EEC), several rivers in the UK have been designated Special Areas of Conservation (SACs) because they support important populations of fish species. Several factors need to be considered when establishing survey protocols to assess the conservation status of fish species in these rivers.

It is important to understand the biology and habitat requirements of fish species and to design appropriate monitoring surveys that adequately assess the status of the fish populations. This information can, in turn, provide the basis for establishing sustainable conservation targets for specific stocks, a process known as condition assessment.

Favourable condition of fish species in SAC rivers is assessed using three criteria. The first relates to density of fish in various life stages against pre‐set targets, assuming that an appropriate number of sites is surveyed to account for natural spatial and temporal variations in fish populations. The second is evaluation of the demographic structure to demonstrate continued recruitment success. Third, by mapping the distribution of the target species in individual rivers and where favourable condition is only achieved where there has been no reduction in the distribution range river between surveys.

The framework described was developed from limited survey data. As more monitoring and assessment data become available, the threshold criteria for favourable condition for each species should be improved, and uncertainty in the procedures reduced.

Copyright © 2008 John Wiley & Sons, Ltd.
Ecology and conservation status of temporary and fluctuating ponds in two areas of southern England
Authors: Bilton D.T. , McAbendroth L.C. , Nicolet P. , Bedford A. , Rundle S.D. , Foggo A. , Ramsay P.M.
Published: September 2008

A high proportion of ponds are temporary in nature, although the biodiversity value of such sites is still poorly recognized. This work explores the plant and macroinvertebrate communities of 76 temporary and fluctuating water bodies in two regions of southern England (Lizard Peninsula, Cornwall and New Forest, Hampshire) that have retained high pond densities. The ecology and conservation status of sites is examined, and comparisons made with ponds elsewhere in England and Wales.

Lizard and New Forest ponds supported 119 plant and 165 macroinvertebrate species respectively. Patterns of community similarity for plants and macroinvertebrates were highly concordant, taxa being related in a similar manner to measured environmental variables including pond area, depth, pH and water chemistry.

Patterns of pond occupancy revealed that most species were locally rare, over half occurring in less than 10% of ponds, and less than 10% being recorded from more than 50% of sites. More than 50% of ponds supported at least one nationally rare plant and almost 75% at least one nationally rare macroinvertebrate. These taxa occupied a wide range of pond types in each region, and did not have predictably different ecologies from common species.

Comparisons with ponds elsewhere in England and Wales revealed that Lizard and New Forest communities are nationally distinct, being most similar to ponds in areas of low intensity agriculture elsewhere in western Britain. Individual ponds in both regions supported more nationally rare taxa, on average, than ponds sampled in the national survey.

Ponds in the two areas have high conservation value, both regionally and nationally, supporting almost 75% of the global species richness of temporary ponds sampled across England and Wales. Within each region, many taxa are found in relatively few sites, and effective conservation of pond biodiversity will require a regional management approach.

Copyright © 2008 John Wiley & Sons, Ltd.
Assessment and propagation of input uncertainty in tree‐based option pricing models
Authors: Gzyl Henryk , Molina German , ter Horst Enrique
Published: September 2008

This paper aims to provide a practical example of assessment and propagation of input uncertainty for option pricing when using tree‐based methods. Input uncertainty is propagated into output uncertainty, reflecting that option prices are as unknown as the inputs they are based on. Option pricing formulas are tools whose validity is conditional not only on how close the model represents reality, but also on the quality of the inputs they use, and those inputs are usually not observable. We show three different approaches to integrating out the model nuisance parameters and show how this translates into model uncertainty in the tree model space for the theoretical option prices. We compare our method with classical calibration‐based results assuming that there is no options market established and no statistical model linking inputs and outputs. These methods can be applied to pricing of instruments for which there is no options market, as well as a methodological tool to account for parameter and model uncertainty in theoretical option pricing. Copyright © 2008 John Wiley & Sons, Ltd.
Hydraulischer Grundbruch: Literaturübersicht und offene Fragen
Authors: Hettler Achim
Published: September 2008

Anlass für den folgenden Beitrag war eine Lücke in den bestehenden Regelwerken für den Fall mit Auflastfiltern beim Nachweis der Sicherheit gegen hydraulischen Grundbruch. Zunächst wird eine Literaturübersicht über wesentliche Arbeiten zur Frage des hydraulischen Grundbruchs mit und ohne Auflastfilter gegeben. Danach werden die Vorgaben aus den maßgebenden Regelwerken zusammengestellt. Erste Ansätze werden vorgestellt, wie seitliche Reibungskräfte in einem Auflastfilter angesetzt werden können, und es werden offene Fragen angesprochen, die in dem darauffolgenden ergänzenden Beitrag von Odenwald und Herten aufgegriffen und behandelt werden.
Standsicherheitsnachweis für Oberflächenabdichtungssysteme von Deponien
Authors: Wudtke Robert‐Balthasar , Werth Katja , Witt Karl Josef
Published: September 2008

Die Standsicherheit von Oberflächenabdichtungen auf Deponieböschungen ist nach aktuellen nationalen und europäischen Normen mit dem Teil sicherheitskonzept zu führen. Der Nachweis wird in Anlehnung an den der Gesamtstandsicherheit im Grenzzustand GEO‐3 (GZ 1C) geführt. Um den Rechenaufwand gering zu halten und Fehlerquellen zu eliminieren, wird empfohlen, auch die Bemessungszugkraft einer evtl. erforderlichen Bewehrung im Grenzzustand GEO‐3 zu ermitteln. Der Beitrag erläutert die Grundlage des Nachweiskonzepts, die Grenzzustandsgleichungen für schichtparalleles Gleiten und die Bemessungs‐/Nachweismethode von Bewehrungselementen. Beim Nachweis der Standsicherheit mit diesem Konzept wird das bisherige Sicherheitsniveau beibehalten. Kernfrage des Nachweises ist weniger die Methode, als vielmehr die Festlegung der effektiven Scherparameter, die über lange Zeiträume unter sich ändernden Bedingungen und Alterung der Materialien in den Kontaktflächen des Systems mobilisiert werden können.
Zur Anwendung der Finite‐Elemente‐Methode bei Baugrubenwänden
Authors: Hettler Achim , Schanz Tom
Published: September 2008

In den vergangenen Jahren hat sich die Finite‐Elemente‐Methode (FEM) zu einem Standardwerkzeug des geotechnischen Ingenieurs entwickelt. Die FEM eignet sich vor allem zur Berechnung von Verformungen und zur Prognose der Gebrauchstauglichkeit auf der Grundlage von charakteristischen Bodenkenngrößen, insbesondere auch bei Baugruben mit schwierigen geometrischen Abmessungen.

Aus dem Berechnungsgang zur Ermittlung der Verformungen können auch charakteristische Einwirkungen bzw. Beanspruchungen für den Nachweis der Tragfähigkeit bestimmt werden. Wie beispielhaft gezeigt wird, stößt die FEM in Verbindung mit dem Nachweisverfahren 2, das in Deutschland mit Ausnahme des Geländebruchs obligatorisch ist, auf Schwierigkeiten bei der Ermittlung von Widerständen, so dass sich in den meisten Fällen ein klassischer Nachweis empfiehlt.
Empfehlung Nr. 10 des Arbeitskreises 3.3 “Versuchstechnik Fels” der Deutschen Gesellschaft für Geotechnik e. V.: Indirekter Zugversuch an Gesteinsproben – Spaltzugversuch
Authors: Lepique Michael
Published: September 2008

Der Arbeitskreis AK 3.3 “Versuchstechnik Fels” der Deutschen Gesellschaft für Geotechnik e. V. erarbeitet Empfehlungen für felsmechanische Labor‐ und Feldversuche sowie Messungen im Gebirge und an Bauwerken. Die vorliegende Neufassung der Empfehlung Nr. 10 behandelt den Spaltzugversuch an Gesteinsprobekörpern und berücksichtigt die Weiterentwicklung der Prüfmaschinen‐ und Versuchstechnik seit der gleichnamigen Empfehlung Nr. 10 von 1985. Es werden die Anforderungen an die Prüfeinrichtung und die Probekörper sowie die Vorgehensweisen für die Durchführung und Auswertung von Spaltzugversuchen festgelegt. Die wesentliche Neuerung besteht darin, dass die Vorgehensweise zur Untersuchung der Anisotropie der Spaltzugfestigkeit von texturiertem Gestein geregelt wird.

Die Spaltzugfestigkeit einer Gesteinsprobe wird im indirekten Zugversuch bestimmt. Ein zylindrischer Probekörper wird durch Streifenlasten bis zum Bruch durch Spalten der Probe belastet. Die Zugfestigkeit wird auf der Grundlage der Elastizitätstheorie ermittelt.
Determination of propafenone hydrochloride by flow‐injection analysis coupled with resonance light scattering detection
Authors: Hu Xiaoli , Xu Dongpo , Liu Shaopu , Liu Zhongfang , Liu Sa
Published: September 2008

A simple, sensitive and rapid flow injection analysis (FIA) method with resonance light scattering (RLS) was described for the determination of propafenone (PPF). The method was based on the ion‐association reaction of 12‐tungstophosphoric acid (TP) with propafenone. In pH 1.0 acidic medium, TP reacted with PPF to form an ion‐associate complex, which resulted in a significant enhancement of RLS intensity. The maximum scattering peak was located at 340 nm, the RLS intensity was proportional to the concentration of PPF in the range 0.003–9.0 µg/mL, and the detection limit (3σ) of 1.0 ng/mL was obtained at a sampling rate of 60 samples/h. The feasible reaction conditions and FIA parameters for the system were optimized. The method proposed in this paper shows satisfactory reproducibility with a relative standard deviation (RSD) of 2.1% for 10 successive determinations of 2.0 µg/mL PPF. The present method had been successfully applied to the determination of PPF in serum samples and pharmaceutical samples. The results obtained were in agreement with the method used in the Chinese Pharmacopoeia. Copyright © 2008 John Wiley & Sons, Ltd.
Computational investigation of kinetics of cross‐linking reactions in proteins: Importance in structure prediction
Authors: Bandyopadhyay Pradipta , Kuntz Irwin D.
Published: September 2008

The determination of protein structure using distance constraints is a new and promising field of study. One implementation involves attaching residues of a protein using a cross‐linking agent, followed by protease digestion, analysis of the resulting peptides by mass spectroscopy, and finally sequence threading to detect the protein folds. In the present work, we carry out computational modeling of the kinetics of cross‐linking reactions in proteins using the master equation approach. The rate constants of the cross‐linking reactions are estimated using the pKas and the solvent‐accessible surface areas of the residues involved. This model is tested with fibroblast growth factor (FGF) and cytochrome C. It is consistent with the initial experimental rate data for individual lysine residues for cytochrome C. Our model captures all observed cross‐links for FGF and almost 90% of the observed cross‐links for cytochrome C, although it also predicts cross‐links that were not observed experimentally (false positives). However, the analysis of the false positive results is complicated by the fact that experimental detection of cross‐links can be difficult and may depend on specific experimental conditions such as pH, ionic strength. Receiver operator characteristic plots showed that our model does a good job in predicting the observed cross‐links. Molecular dynamics simulations showed that for cytochrome C, in general, the two lysines come closer for the observed cross‐links as compared to the false positive ones. For FGF, no such clear pattern exists. The kinetic model and MD simulation can be used to study proposed cross‐linking protocols. © 2008 Wiley Periodicals, Inc. Biopolymers 91: 68–77, 2009.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Mitigating climate change – how do corporate strategies differ?
Authors: Weinhofer Georg , Hoffmann Volker H.
Published: September 2008

Many companies are facing increasing pressure by governments, shareholders and other stakeholders to reduce their CO2 emissions in order to mitigate climate change. The importance of managing CO2 emissions and crafting adequate CO2 strategies has increased for those companies affected. We present a framework that conceptualizes a company's CO2 strategy as the focus on one or a combination of several strategic objectives: CO2 compensation, CO2 reduction and carbon independence. In order to investigate the CO2 strategies of a worldwide sample of 91 electricity producers we perform a content analysis of their answers to the Carbon Disclosure Project (CDP). We demonstrate the measures the companies take to manage their emissions, the CO2 strategies they adopt and antecedents that influence these strategies. We find that half of the companies take parallel emission management measures that aim at all three strategic objectives, while the other half pursue selected objectives only. We also find that companies with different CO2 strategies significantly differ in terms of regional affiliation, company size and absolute amount of CO2 emissions, while we could not identify a significant difference in relative CO2 emissions. Copyright © 2008 John Wiley & Sons, Ltd and ERP Environment.
N‐Methyl Scanning Mutagenesis Generates Protease‐Resistant G Protein Ligands with Improved Affinity and Selectivity
Authors: Fiacco Stephen V. , Roberts Richard W.
Published: September 2008

Scanning for bioavailability: N‐methyl incorporation does not have to be at the scissile bond to dramatically enhance protease resistance. N‐methyl scanning around the scissile bond has yielded compounds that are also more selective and bind with higher affinity.
DNA with Branched Internal Side Chains: Synthesis of 5‐Tripropargylamine‐dU and Conjugation by an Azide‐Alkyne Double Click Reaction
Authors: Sirivolu Venkata Ramana , Chittepu Padmaja , Seela Frank
Published: September 2008

5‐Tripropargylamine‐2′‐deoxyuridine (1 a) containing two terminal triple bonds was synthesized by a Pd‐assisted Sonogashira cross‐coupling reaction and was subsequently converted into the corresponding phosphoramidite building block (9) and employed in solid‐phase oligonucleotide synthesis. Tm experiments demonstrate that the presence of covalently attached branched tripropargylamine residues has a positive effect on the base pair stability. The two terminal CC bonds of modified DNA were functionalized by means of CuI‐mediated 1,3‐dipolar cycloaddition reactions (click chemistry) with azides such as 3‐azido‐7‐hydroxycoumarin or 3′‐azido‐3′‐deoxythymidine (AZT) both in solution and on solid support. In particular, with the nonfluorescent 3‐azido‐7‐hydroxycoumarin a strongly fluorescent oligonucleotide bis‐dye conjugate was generated. For comparison, the N(3)‐propargylated 2′‐deoxyuridine 2 was prepared from 2′‐deoxyuridine and propargyl bromide and incorporated into DNA. The two terminal triple bonds of 1 a allow the simultaneous post‐modification of DNA by two reporter molecules and can be applied to almost any azido derivatives (oligonucleotides, proteins, polysaccharides etc.) including those forming dendrimeric side chains.