bluuebunny/crossref_metadata_2025 huggingface dataset:
Weakening of Alkali‐Activated Metakaolin During Aging Investigated by the Molybdate Method and Infrared Absorption Spectroscopy
Authors: Rüscher Claus H. , Mielcarek Elzbieta , Lutz Wolfgang , Ritzmann Attila , Kriven Waltraud M.
Published: April 2010

Aluminosilicate gels were synthesized by mixing metakaolin with potassium water glass solution. Mechanical strength values showed a strong increase between 25 and 100 h but decreased again above 200 h for aging at 25°C. A similar curve was observed during aging at 50°C but the maximum strength shifted to shorter time. Aging at 90° and 130°C revealed only the decreasing wing in mechanical strength. The strengthening and weakening during aging at 25°C were further investigated by the molybdate method and infrared absorption spectroscopy. The results indicate basically that different time‐dependent formations of two structural units dominate the mechanical properties: (i) A fast formation of longer (polymeric) silicate chains is enforced by the consumption of hydroxide in the solution of metakaolin up to about 25 h of aging. (ii) An aluminosilicate network grows slowly and encloses the chain‐like units giving rise to an initial increase in strength within 100 h. During further aging the destruction of the polysilicate chains weakens the geopolymer. The destruction of the chain‐like units is explained by the increasing amount of hydroxide produced during network condensation. The results imply that the same reactions occur for aging at a higher temperature but on faster time scales.
When Cross‐Examination Offends: How Men and Women Assess Intrusive Questioning of Male and Female Expert Witnesses
Authors: Larson Bridget A. , Brodsky Stanley L.
Published: April 2010

Personally intrusive questioning during cross‐examination has become commonplace. The differential impact of this questioning on female vs. male experts was the focus in this study, thus these questions are referred to as gender‐intrusive questions. The results demonstrated that the female expert was rated as less confident, trustworthy, likable, believable, and credible than the male expert. The male and female experts were both rated as more credible, trustworthy, and believable when subjected to gender‐intrusive questions. Furthermore, the use of these questions left the jurors with a negative impression of the prosecuting attorney and his case. Jury members were more likely to believe that the evidence exhibited the most support for the defense's case when the witness was subjected to gender‐intrusive questioning.
Going Green? Modeling the Impact of Environmental Concerns and Perceptions of Transportation Alternatives on Decisions to Drive
Authors: Gardner Benjamin , Abraham Charles
Published: April 2010

A theory‐of‐planned‐behavior‐based model of intra‐city driving incorporating cognitions concerning non‐car transportation use, personal and descriptive norms, and the environment was tested. Participants were 190 residents of a UK city with good non‐car travel infrastructure. Intention predicted 57% of the variance in behavior. In addition, 49% of intention variance was predicted by car‐use attitudes, perceived behavioral control, descriptive norms, non‐car‐use attitudes, subjective norms, and personal norms. Concern and efficacy for reducing car‐related environmental problems were associated with non‐car attitudes and personal norms. Results demonstrate the importance of modeling transportation choice on cognitions relating to both car use and alternative transportation.
Activation and Automaticity of Colonial Mentality
Authors: David E. J. R. , Okazaki Sumie
Published: April 2010

Among Filipino Americans, colonial mentality (CM) is characterized by automatic preference for anything American and automatic rejection of anything Filipino that may be manifested overtly and covertly. Thus, 3 studies were conducted to test CM's theorized covertness and automaticity. Study 1 attempted to activate and capture the existence of CM‐consistent cultural knowledge schemas; Study 2 investigated whether CM may be automatically activated using a lexical decision task; and Study 3 tested whether Filipino Americans have associated pleasantness with anything American, and unpleasantness with anything Filipino using the Implicit Association Test. The results suggest that many Filipino Americans hold a CM‐consistent cultural knowledge schema, and that CM may be conceptualized as a set of automatic associations that cannot be consciously controlled.
Empathy, Knowledge, and Personal Distress as Correlates of HIV‐/AIDS‐Related Stigmatization and Discrimination
Authors: Olapegba Peter Olamakinde
Published: April 2010

This study investigated the influence of empathy, knowledge, and personal distress on HIV‐/AIDS‐related stigmatization and discrimination in a normal population (N = 346). Participants ranging in age from 18 to 69 years responded to a validated questionnaire. The results showed a significant main and joint influence of empathy, knowledge, and personal distress on stigmatization and discrimination. Stigmatization and discrimination are thus identified as great obstacles in the fight against and prevention of HIV/AIDS. Stakeholders in the HIV/AIDS arena should embark on mass education to increase knowledge of HIV/AIDS; also attitudinal change programs should be initiated, while health institutions should be effectively monitored to ensure best practices.
ENTEROTOXIN‐PRODUCING STAPHYLOCOCCUS STRAINS ASSOCIATED WITH SOUTH AFRICAN BILTONG AT POINT OF SALE
Authors: MHLAMBI S.G. , NAIDOO K. , LINDSAY D.
Published: April 2010

This study assessed the presence of Staphylococcus strains associated with the ready‐to‐eat meat product, biltong, (n = 26), at point of sale. Traditional beef, spiced/flavored beef, chicken and venison biltong varieties were purchased from local retailers, butcheries and street vendors. Samples were prepared for aerobic counts, yeast counts and presumptive Staphylococcus counts using standard spread plating techniques. Presumptive Staphylococcus aureus strains were selected using Pake's disk and characterized using a dichotomous key. Eleven of these strains were selected and further identified using 16S rDNA sequence analysis. Five of these, representing different species of Staphylococcus, were tested for enterotoxin production using the Set‐RPLA toxin detection kit. Of the three biltong varieties, the chicken and venison consistently showed the highest counts across all types of media used (ca. 7 log colony forming units (cfu)/g), while the spiced biltong varieties generally showed lowest counts (ca. 5.5 log cfu/g). All 11 strains were identified by 16S rDNA sequence analysis as members of the Staphylococcus genus. Of these, five clustered with other Staphylococcus equorum strains, two with the Staphylococcus saprophyticus/Staphylococcus xylosus group, two with Staphylococcus succinus isolates and one each with Staphylococcus piscifermentans or S. aureus clusters. Enterotoxins staphylococcal enterotoxin B (SEB) and staphylococcal enterotoxin D (SED) were produced by two of the isolates indicating foodborne illness implications.

PRACTICAL APPLICATIONS

Biltong is a South African dried meat commodity which is a national favorite. However, very few studies have been conducted on the microbiological safety of biltong, as it has traditionally been seen as “safe” due to a low water activity (0.77) and pH (5.5). This preliminary study identified the presence of various strains of Staphylococcus associated with biltong product at point of sale in South Africa, and showed that some of these isolates, including Staphylococcus aureus and Staphylococcus equorum strains, held foodborne illness implications as they produced staphylococcal enterotoxins. This is the first such report on the presence of enterotoxin‐producing Staphylococcus in biltong and contributes new knowledge to food processors in South Africa relating to production of safe dried meat products.
Efficacy of oral prednisolone and dexamethasone in horses with recurrent airway obstruction in the presence of continuous antigen exposure
Authors: LECLERE M. , LEFEBVRE‐LAVOIE J. , BEAUCHAMP G. , LAVOIE J.‐P.
Published: April 2010

Reasons for performing study:Orally administered prednisolone and dexamethasone are used commonly in the treatment of recurrent airway obstruction (RAO) in horses. However, the efficacy of prednisolone in improving pulmonary function during continuous antigen exposure has not been evaluated critically and there is little evidence supporting the efficacy of low‐dose oral dexamethasone in the same conditions.

Hypothesis:Oral prednisolone and dexamethasone improve pulmonary function in RAO under conditions of continuous antigen exposure, and dexamethasone is more effective than prednisolone at commonly used dosages.

Methods:Using a randomised crossover design, prednisolone (2 mg/kg bwt) and dexamethasone (0.05 mg/kg bwt) were administeredper os, s.i.d. for 7 days, to 7 horses during clinical exacerbation of the disease. Maximal difference in transpulmonary pressure (ΔPL), lung resistance (RL) and elastance (EL) were measured before and after 3 and 7 days of treatment.

Results:Prednisolone and dexamethasone improved pulmonary function significantly. However, the improvement was of greater magnitude after 3 and 7 days of treatment with dexamethasone compared to prednisolone. Also, after 7 days of treatment with dexamethasone, ΔPLand RLwere not different from values obtained when horses were on pasture, while all 3 pulmonary function parameters remained different from pasture values after prednisolone treatment.

Conclusions:Both corticosteroids improve pulmonary function, in spite of continuous antigen exposure. However, oral dexamethasone at 0.05 mg/kg bwt is more effective than prednisolone at 2 mg/kg bwt in the treatment of RAO.

Potential relevance:Prednisolone was shown, for the first time, to our knowledge, to improve the pulmonary function of horses with RAO in the presence of continuous antigen exposure. This study also demonstrates the efficacy of low‐dose oral dexamethasone in reversing airway obstruction in these conditions.
Post mortem survey of peripheral dental caries in 510 Swedish horses
Authors: GERE I. , DIXON P. M.
Published: April 2010

Reasons for performing study: Peripheral caries (PC) of equine teeth is a poorly described disorder that can cause serious clinical problems if it progresses.

Objectives: To assess the prevalence, sites and severity of PC in a population of Swedish horses.

Methods: A post mortem study of 510 equine skulls was performed in 2 Swedish equine abattoirs.

Results: PC only affected the cheek teeth (CT) and was present in 6.1% (31/510) of skulls. It affected mainly the peripheral cementum, and 87% of PC in the 29 affected mature horses occurred in the 3 caudal CT (Triadan 09‐11). Concurrent infundibular caries involving most maxillary CT (mean 9.7/skull) was present in 32% of skulls affected with PC. Trotting horses (mean age 8.1 years) believed to be on a high concentrate and silage diet were preferentially affected with PC in this population. Food was usually tightly adherent to the PC lesions and this feature may have promoted the progression of the disease. Significantly increased levels of diastemata were present in PC‐affected horses, and periodontal disease was present in areas adjacent to some PC lesions.

Conclusions: PC is a relatively common disorder of horses under certain management conditions that can progress to cause serious dental disorders, especially if concurrent, widespread infundibular caries is present.

Potential relevance: Equine clinicians should be aware of this significant dental disorder and research into its aetiopathogenesis, possible prevention and treatment are required.
Exploring lay perceptions of the causes of crib‐biting/windsucking behaviour in horses
Authors: LITVA A. , ROBINSON C. S. , ARCHER D. C.
Published: April 2010

Reasons for performing study:Crib‐biting/windsucking behaviour has important consequences for equine health and welfare. Lay perceptions of health and illness are of interest to medical sociologists, providing important information to medical practitioners, but have infrequently been applied in veterinary research.

Objectives:To demonstrate how lay epidemiology can be applied within veterinary research by exploring the lay perceptions regarding the causes of crib‐biting/windsucking behaviour in horses.

Methods:Informants were recruited from professional and amateur horse owners who had or had not owned/cared for a horse that exhibited crib‐biting/windsucking behaviour. In‐depth interviews were used to examine perceptions about the development of this behaviour within each group until a ‘saturation’ of themes emerged.

Results:The main themes that emerged as causes of crib‐biting/windsucking behaviour were ‘boredom’, ‘stress’ and ‘habit/addiction’. In the group of owners/carers who did not have direct experience of this type of behaviour, ‘copying’ from other horses emerged as a strong theme and they stated that they would not wish to own a crib‐biting/windsucking horse. In contrast, those who had direct experience of horses demonstrating this behaviour did not believe copying was a cause based on their own observations and would not be put off purchasing or caring for another horse displaying this behaviour.

Conclusions:Perceptions about what causes crib‐biting/windsucking was influenced by whether or not informants had personal experience of horses demonstrating this behaviour. The three main themes that emerged have some justification based on current research and highlight the need for further investigation into the underlying pathophysiology of crib‐biting/windsucking behaviour.

Potential relevance:Qualitative approaches to health, disease and behaviour have an important role in the medical field and are applicable to veterinary research.
Kinematics of saddle and rider in high‐level dressage horses performing collected walk on a treadmill
Authors: BYSTRÖM A. , RHODIN M. , Von PEINEN K. , WEISHAUPT M. A. , ROEPSTORFF L.
Published: April 2010

Reasons for performing the study:The kinematics of the saddle and rider have not been thoroughly described at the walk.

Objective:To describe saddle and rider movements during collected walk in a group of high‐level dressage horses and riders.

Methods:Seven high‐level dressage horses and riders were subjected to kinematic measurements while performing collected walk on a treadmill. Movements of the saddle and rider's pelvis, upper body and head were analysed in a rigid body model. Projection angles were determined for the rider's arms and legs, and the neck and trunk of the horse. Distances between selected markers were used to describe rider position in relation to the horse and saddle.

Results:During the first half of each hindlimb stance the saddle rotated cranially around the transverse axis, i.e. the front part was lowered in relation to the hind part and the rider's pelvis rotated caudally, i.e. in the opposite direction. The rider's seat moved forwards while the rider's neck and feet moved backwards. During the second half of hindlimb stance these movements were reversed.

Conclusion:The saddles and riders of high‐level dressage horses follow a common movement pattern at collected walk. The movements of the saddle and rider are clearly related to the movements of the horse, both within and outside the sagittal plane.

Potential relevance:The literature suggests that the rider's influence on the movement pattern of the horse is the strongest at walk. For assessment of the horse‐rider interaction in dressage horses presented for unsatisfactory performance, evaluations at walk may therefore be the most rewarding. Basic knowledge about rider and saddle movements in well‐performing horses is likely to be supportive to this task.
The distal sesamoidean impar ligament: Comparison between its appearance on magnetic resonance imaging and histology of the axial third of the ligament
Authors: DYSON S. , POOL R. , BLUNDEN T. , MURRAY R.
Published: April 2010

Reasons for performing study:There is limited knowledge about the interpretation of alterations in the distal sesamoidean impar ligament (DSIL) detected using magnetic resonance imaging (MRI) and their correlation with histopathology.

Hypotheses:There would be: 1) a correlation between histopathology and MRI findings; and 2) a relationship between MR abnormalities at the origin and the insertion of the DSIL, between insertion and body; and origin and body.

Methods:Fifty limbs from 28 horses were examined using high‐field MRI and histopathology. MR abnormalities of the DSIL, its origin on the navicular bone and its insertion on the distal phalanx were graded. Sections of the axial third of the DSIL were examined histologically and graded according to fibre orientation, integrity of fibroblasts, collagen architecture and vascularity. Associations between MRI and histology findings were tested by Spearman rank correlation and Chi‐squared tests.

Results:There were significant correlations between the presence of a cystic structure in the distal third of the navicular bone, or a distal border fragment, or increased signal intensity in fat suppressed images at the insertion of the DSIL on the distal phalanx and the histological grade of the body of the DSIL. There were significant associations between a cystic structure in the distal third of the navicular bone and the presence of either a distal border fragment or entheseous new bone at the insertion of the DSIL, swelling of the DSIL and increased signal intensity in the DSIL in fat suppressed images; between distal elongation of the flexor border of the navicular bone and the presence of one or more distal border fragments and between swelling of the body of the DSIL and irregularity of its palmar border or increased signal intensity in fat suppressed images in the DSIL.

Conclusions and clinical relevance:The presence of a cystic structure in the distal third of the navicular bone detected using MRI, a distal border fragment or increased signal intensity at the insertion of the DSIL are suggestive of significant alterations in the infrastructure of the DSIL.
Effect of temperature on race times on a synthetic surface
Authors: PETERSON M. L. , REISER II R. F. , KUO P.‐H. , RADFORD D. W. , Mc ilwraith C. W.
Published: April 2010

Reasons for performing study:Differences in racing times have been noted on synthetic track surfaces that appear to depend on the temperature of the track. No published study to date has considered this effect in a systematic manner.

Objectives:To investigate the relationship between temperature of track and speed of horses racing on a synthetic surface. Potential changes in the wax component of the synthetic track were investigated as one possible cause of changes in the track speed at the temperatures observed.

Methods:At Del Mar racetrack (California, USA), the air, surface and subsurface temperatures at 4 depths in the synthetic race surface were measured periodically throughout the day over a 42 day period. The 6 furlong (1.2 km) race (afternoon) and fast training ‘work’ (morning) times were also compiled. Samples of the track were obtained and the wax separated using a solvent separation technique. Differential scanning calorimetry was used to determine the range of temperatures at which the wax from the track underwent softening and other material changes. Transformation temperatures were compared to temperatures acquired from the track to evaluate the likelihood of changes in the wax properties during racing.

Results:Average air, surface and subsurface temperatures changed significantly throughout the day. Temperatures were higher during the afternoon race sessions and race times were significantly slower compared to morning work times. Temperatures at which some of the components of the wax began to soften were found to be within the range of temperature measured during track operation.

Conclusions:A correlation was found between temperature of the synthetic track and speed of horse. Wax separated from the track showed that the temperatures experienced in the surface during normal operation exceed the temperatures at which the wax begins to experience thermal transformation. It is therefore hypothesised that the wax may be a cause of the observed changes in the track performance.

Potential relevance:Future work should include a study of components of the synthetic track responsible for the change and epidemiological association of risk of injury.
Intralesional bovine papillomavirus DNA loads reflect severity of equine sarcoid disease
Authors: HARALAMBUS R. , BURGSTALLER J. , KLUKOWSKA‐RÖTZLER J. , STEINBORN R. , BUCHINGER S. , GERBER V. , BRANDT S.
Published: April 2010

Reasons for performing study: Sarcoids are nonmetastasising, yet locally aggressive skin tumours that constitute the most frequent neoplasm in equids. Infection by bovine papillomaviruses types 1 and 2 (BPV‐1, BPV‐2) has been recognised as major causative factor in sarcoid pathogenesis, but a possible correlation of intralesional virus load with disease severity has not been established thus far.

Hypothesis: Given the pathogenic role of BPV‐1 and BPV‐2 in sarcoid disease, we suggest that intralesional viral DNA concentration may reflect the degree of affection.

Methods: Severity of disease was addressed by recording the tumour growth kinetics, lesion number and tumour type for 37 sarcoid‐bearing horses and one donkey. Viral load was estimated via quantitative real‐time PCR (qPCR) of the E2, E5, L1 and L2 genes from the BPV‐1/‐2 genome for one randomly selected lesion per horse and correlated with disease severity.

Results: Quantitative PCR against E2 identified viral DNA concentrations ranging from 0–556 copies/tumour cell. Of 16 horses affected by quiescent, slowly growing single tumours or multiple mild‐type lesions, 15 showed a viral load up to 1.4 copies per cell. In stark contrast, all equids (22/22) bearing rapidly growing and/or multiple aggressive sarcoids had a viral load between 3 and 569 copies per cell. Consistent results were obtained with qPCR against E5, L1 and L2.

Conclusions: While tumours of the same clinical type carried variable virus load, confirming that viral titre does not determine clinical appearance, we identified a highly significant correlation between intralesional viral load and disease severity.

Potential relevance: The rapid determination of BPV viral load will give a reliable marker for disease severity and may also be considered when establishing a therapeutic strategy.
Diagnostic utility of computed tomography imaging in equine intracranial conditions
Authors: LACOMBE V. A. , SOGARO‐ROBINSON C. , REED S. M.
Published: April 2010

Reasons for performing study: The use of computer tomography (CT) and contrast‐enhanced CT (CCT) to image the head is common. However, the validity of CT as a neurodiagnostic indicator of intracranial diseases in horses is unknown.

Objective: To define the validity of CT and CCT in horses with suspected intracranial disorders.

Methods: The validity of CT imaging was estimated by comparing clinical, clinicopathological and histopathological findings to CT findings in 15 horses presented for intracranial disorders, for which pre‐ and post contrast CT images and post mortem examination of the brain and skull were reviewed. Post mortem examination (gross and histopathological examination) was considered as the gold standard; and sensitivity, specificity, predictive values, likelihood ratios, and pre‐ and post test probabilities were calculated.

Results: All horses had abnormal neurological examinations on admission. Computer tomography imaging identified intracranial lesions in 8 horses, and included masses (oligodendroglioma, adenocarcinoma and cholesterinic granulomas), acute haemorrhage and skull fractures. Computer tomography imaging failed to identify intracranial lesions in 6 cases, which included meningitis, meningoencephalitis and nonacute haemorrhage. Lesions not recognised by CT were also not evident on gross examination but were identified by histopathological examination of the brain. Post mortem examination of the brain and skull was unremarkable in one horse, for which cranial CT imaging was normal (specificity, 100%). Therefore, the odds of having an intracranial lesion after an abnormal CT were very high. In contrast, there was a moderate sensitivity (57.1%, 95% confidence interval: 29.6–81.2).

Conclusions and potential relevance: CT was an excellent neurodiagnostic tool in identifying skull fractures, intracranial space‐occupying lesions (e.g. neoplasia) and acute haemorrhage and allows to rule in intracranial disorders. However, CT showed limited sensitivity in identifying inflammatory disorders and small parenchymal lesions in the equine brain, which was not further detectable after contrast administration.
Outcome and long‐term follow‐up of 20 horses undergoing surgery for caecal impaction: A retrospective study (2000–2008)
Authors: SMITH L. C. R. , PAYNE R. J. , BOYS SMITH S. J. , BATHE A. P. , GREET T. R. C.
Published: April 2010

Reasons for performing study:If untreated, caecal impaction may progress to rupture of the caecum and reports of long‐term outcome for horses undergoing surgery for caecal impaction are required.

Objectives:To describe short‐ and long‐term complication rates for horses undergoing surgery for caecal impaction in an otherwise life‐threatening gastrointestinal condition.

Methods:Case records were reviewed for horses undergoing surgery for caecal impaction. Horses were included in the study if an abnormally large, fluid‐distended or feed‐impacted caecum was the primary diagnosis at surgery and excluded if the caecum had already ruptured upon opening the abdomen, necessitating euthanasia. Short‐term follow‐up data were obtained from clinical records; and included complications, repeat celiotomy and survival to discharge. Long‐term survival was defined as survival for >1 year post operatively. Long‐term follow‐up data were obtained through telephone interviews with owners and referring veterinary surgeons. Survival, occurrence of post operative colic and subsequent use of the horse were recorded.

Results:Twenty horses underwent surgery for caecal impaction: 16 horses underwent caecal bypass (typhlotomy and removal of caecal contents, ileal transection followed by ileocolostomy); 3 underwent typhlotomy alone; and one horse underwent typhlotomy followed by a second procedure where caecal bypass was performed. Five horses (25%) were admitted for colic evaluation with primary caecal impactions, in 10/20 (50%) of cases the impaction was secondary to previous orthopaedic surgery and in 5/20 (25%) caecal impaction was identified at repeat celiotomy following a previous colic surgery. Sixty‐five percent (13/20) of horses survived to discharge; 11/13 (85%) of horses discharged survived long term; 100% (3/3) horses that received typhlotomy alone were discharged and survived long term.

Conclusions:The prognosis following caecal impaction surgery is fair, if the horse survives to discharge then prognosis for long‐term survival is good.

Potential relevance:Surgery for caecal impaction carries a fair prognosis for a potentially life threatening disease, in particular where caecal dysfunction is suspected.
Labs for the Matter & Interactions curriculum
Authors: Beichner Robert , Chabay Ruth , Sherwood Bruce
Published: April 2010

The Matter & Interactions curriculum for a calculus-based introductory physics course emphasizes the power of a small number of fundamental principles, incorporates the atomic nature of matter throughout, and introduces students to computational modeling. The main goal of the laboratory portion of this curriculum is for students to see fundamental principles in action. From this goal flow subgoals that have led to the development of laboratory activities that include several novel genres.
Measuring the speed of light using beating longitudinal modes in an open-cavity HeNe laser
Authors: D’Orazio Daniel J. , Pearson Mark J. , Schultz Justin T. , Sidor Daniel , Best Michael W. , Goodfellow Kenneth M. , Scholten Robert E. , White James D.
Published: April 2010

We describe an undergraduate laboratory that combines an accurate measurement of the speed of light, a fundamental investigation of a basic laser system, and a nontrivial use of statistical analysis. Students grapple with the existence of longitudinal modes in a laser cavity as they change the cavity length of an adjustable-cavity HeNe laser and tune the cavity to produce lasing in the TEM00 mode. For appropriate laser cavity lengths, the laser gain curve of a HeNe laser allows the simultaneous operation of multiple longitudinal modes. The difference frequency between the modes is measured using a self-heterodyne detection with a diode photodetector and a radio frequency spectrum analyzer. Asymmetric effects due to frequency pushing and frequency pulling, as well as transverse modes, are minimized by simultaneously monitoring and adjusting the mode structure as viewed with a Fabry–Pérot interferometer. The frequency spacing of longitudinal modes is proportional to the inverse of the cavity length with a proportionality constant equal to half the speed of light. By changing the length of the cavity, without changing the path length within the HeNe gas, the speed of light in air can be measured to be (2.9972±0.0002)×108 m/s, which is to high enough precision to distinguish between the speed of light in air and in vacuum.
A simple optical probe of transient heat conduction
Authors: Brody Jed , Andreae Phillip , Robinson C. Andrew
Published: April 2010

We use a laser beam and a stopwatch to investigate transient heat conduction in Plexiglas and glycerol samples chilled by ice water. The deflection of the laser beam is proportional to the thermal gradient in the sample. Measurements of the beam deflection allow us to calculate the thermal gradient as a function of time. Our empirical results fit the theoretical predictions very well and show an initial increase in the thermal gradient followed by a gradual decrease as the entire sample approaches the temperature of ice water. The procedure is simple and can be used as a lecture demonstration, an afternoon’s experiment, or an extended investigation in an advanced laboratory course.
Low-voltage polyphasic circuits
Authors: Baird William H. , Jaynes Michael L.
Published: April 2010

Experimentation with polyphasic voltages is greatly simplified when microcontrollers are used to generate multiple square waves with fixed phase offsets. Each square wave is sent through a simple second-order Sallen–Key filter to produce an approximately sinusoidal voltage signal. The microcontroller allows the reproduction of split-phase and three-phase voltage relationships, mirroring those commonly distributed on the North American power grid, at safe voltage levels.
Climate change in a shoebox: Right result, wrong physics
Authors: Wagoner Paul , Liu Chunhua , Tobin R. G.
Published: April 2010

Classroom experiments that purport to demonstrate the role of carbon dioxide’s far-infrared absorption in global climate change are more subtle than is commonly appreciated. We show, using both experimental results and theoretical analysis, that one such experiment demonstrates an entirely different phenomenon: The greater density of carbon dioxide compared to air reduces heat transfer by suppressing convective mixing with the ambient air. Other related experiments are subject to similar concerns. Argon, which has a density close to that of carbon dioxide but no infrared absorption, provides a valuable experimental control for separating radiative from convective effects. A simple analytical model for estimating the magnitude of the radiative greenhouse effect is presented, and the effect is shown to be very small for most tabletop experiments.
Three-dimensional standing waves in a microwave oven
Authors: Kamol S. , Limsuwan P. , Onreabroy W.
Published: April 2010

A microwave oven operating at a frequency of 2.45 GHz was designed for demonstrating three-dimensional standing waves. The three-dimensional standing wave patterns formed on cobalt chloride paper placed at the center of the oven chamber were examined. The images on the cobalt chloride paper corresponding to antinodes of the standing waves were recorded by a digital camera after turning on the microwave oven. The results show that the numbers of antinodes of the standing waves in each plane agree with those of the theoretical calculation of the electric field distribution in the oven chamber.
Qubit quantum mechanics with correlated-photon experiments
Authors: Galvez Enrique J.
Published: April 2010

A matrix-based formalism is used to explain the results of undergraduate level quantum mechanics experiments with correlated photons. The article includes new variations of experiments and new results. A discussion of our experience with a correlated-photon laboratory component for an undergraduate course on quantum mechanics is presented.
Introductory labs on the vector nature of force and acceleration
Authors: Kanim Stephen E. , Subero Keron
Published: April 2010

We discuss the use of long-exposure digital photography in introductory mechanics laboratories. Students at New Mexico State University use inexpensive digital cameras to record the motion of objects with attached blinking light emitting diodes. These photographs are used to make inferences about the velocity and acceleration of the moving object. We use the analysis of these photographs to promote student understanding of the vector nature of kinematics quantities. In subsequent laboratories we build on this understanding to help students relate the acceleration vector for a moving object to the net force vector for that object. We give details about the equipment we use and describe the sequence of activities that we have developed for a two-dimensional motion laboratory and for a laboratory on Newton’s second law. Finally we present some pre- and post-test data on questions related to the concepts underlying these laboratories.
Response to Comment on “Modafinil Shifts Human Locus Coeruleus to Low-Tonic, High-Phasic Activity During Functional MRI”
Authors: Minzenberg Michael J. , Watrous Andrew J. , Yoon Jong H. , La Christian , Ursu Stefan , Carter Cameron S.
Published: April 2010

Contrary to the arguments put forth by Astafiev
et al
., our new analyses and high-resolution replication show that modulation of brain activity by the cognitive enhancing drug modafinil indeed localizes to the locus coeruleus. The authors’ critical stance regarding blood oxygen level–dependent imaging in the brainstem does not follow from their data.
Divided Representation of Concurrent Goals in the Human Frontal Lobes
Authors: Charron Sylvain , Koechlin Etienne
Published: April 2010

Simultaneously Serving Two Goals

What are the neuronal mechanisms underlying dual-task performance?
Charron and Koechlin
(p.
360
) used functional magnetic resonance imaging to study this question under conditions of varying incentive for two tasks. Subjects performed letter-matching tasks either sequentially or concurrently. Reward value for performance of each of the two tasks was manipulated orthogonally. Under conditions of single-task (sequential) performance, they observed bilateral brain activity in the dorsal anterior cingulate and the premotor cortex that correlated with the reward value of the current task. However, under dual-task conditions, activity in these regions on the left corresponded to primary-task reward performance, while on the right, activity corresponded to secondary-task performance. Under dual-task conditions, both reward and stimulus-response representations are thus segregated according to hemisphere.
Dilithioplumbole: A Lead-Bearing Aromatic Cyclopentadienyl Analog
Authors: Saito Masaichi , Sakaguchi Masafumi , Tajima Tomoyuki , Ishimura Kazuya , Nagase Shigeru , Hada Masahiko
Published: April 2010

Aromatic Lead

The bond stabilization, or aromaticity, observed in cyclic carbon molecules, such as benzene, relies on delocalization of electrons around the ring. Although electron distributions in heavier elements can complicate this arrangement,

Saito
et al.

(p.
339
) show that even lead, one of the heaviest metals, is able to participate in an otherwise carbon-based aromatic network. In an analog of the well-studied cyclopentadienyl anion, one carbon atom was replaced with lead, and the framework stabilized by appending phenyl groups to the other four carbons. Crystallography revealed a planar structure, which together with spectroscopic data and theoretical calculations confirmed the aromatic character of the product.
Tracking Earth's Energy
Authors: Trenberth Kevin E. , Fasullo John T.
Published: April 2010

Where has the energy from global warming gone?
Why Science?

Art + Science Now
by Stephen Wilson

Thames and Hudson, New York, 2010. 208 pp. $50, C$63, £29.95. ISBN 9780500238684.
Authors: Edwards David
Published: April 2010

Wilson surveys contemporary work from around the world that draws on molecular biology, kinetics, robotics, physics, information technology, living systems, and other laboratory research.
Does REDD+ Threaten to Recentralize Forest Governance?
Authors: Phelps Jacob , Webb Edward L. , Agrawal Arun
Published: April 2010

A major new approach to emissions mitigation may interrupt a promising trend toward decentralized forest management.
Common U.S. Math Standards
Authors: Daro Philip , McCallum William , Zimba Jason
Published: April 2010

The United States has never had national standards or curricula for mathematics. Instead, each state decides, for example, what version of high-school algebra should be taught and how to assess whether students have learned it. In March 2010, the National Governors Association and the Council of Chief State School Officers released Common Core State Standards (CCSS) for English language arts and mathematics (
www.corestandards.org
). The goal is to have all states adopt these as their standards, making more uniform the knowledge and skills expectations for students in preparation for success in college and careers.
Report Calls for Improvements At Livermore's Giant Laser
Authors: Kintisch Eli
Published: April 2010

A new U.S. government audit of the National Ignition Facility at Lawrence Livermore National Laboratory says the $4 billion behemoth faces "scientific and technical challenges and management weaknesses." But scientists associated with the project believe that the machine will do great science if Congress gives it a chance to flex its muscles.
Sean Carroll and the Evolution of an Education Maven
Authors: Pennisi Elizabeth
Published: April 2010

Sean Carroll, a molecular biologist at the University of Wisconsin, Madison, was named vice president for science education at the Howard Hughes Medical Institute last week.
Science
caught up with Carroll to ask him about his new job.
Telescopes for the People
Authors: Bohannon John
Published: April 2010

The ultimate aim of the International Year of Astronomy 2009 was "to help the citizens of the world rediscover their place in the universe." What better way to do that than give them their own telescopes?
Galileo in Senegal
Authors: Bohannon John
Published: April 2010

The Gonzo Scientist travels to Senegal with an astrophysicist to deliver the universe to remote villagers.
Chasing a Disease to the Vanishing Point
Authors: Couzin-Frankel Jennifer
Published: April 2010

Genetic testing is making a rare disease, familial dysautonomia, even rarer. At the same time, more tools than ever are available to study it.
Besting Johnny Appleseed
Authors: Kean Sam
Published: April 2010

With a few tricks, and a lot of patience, fruit geneticists are undoing the work of an American legend.
Nanogenerators Tap Waste Energy To Power Ultrasmall Electronics
Authors: Service Robert F.
Published: April 2010

Tiny devices that convert movements into electricity won't power cities. But they may soon be efficient enough to power arrays of invisible sensors and hand-held electronics.
LIFE SCIENCE TECHNOLOGIES: An Ever-Brighter Future for Fluorescence
Authors: Harding Anne
Published: April 2010

New, less toxic fluorescent proteins and tags, and strategies for delivering them, are allowing researchers to watch processes within cells never before observed. Industry and academia are now working to not only detect these processes, but also localize and quantify them.
Binding to Gangliosides Containing
N
-Acetylneuraminic Acid Is Sufficient To Mediate the Immunomodulatory Properties of the Nontoxic Mucosal Adjuvant LT-IIb(T13I)
Authors: Nawar Hesham F. , Berenson Charles S. , Hajishengallis George , Takematsu Hiromu , Mandell Lorrie , Clare Ragina L. , Connell Terry D.
Published: April 2010

By use of a mouse mucosal immunization model, LT-IIb(T13I), a nontoxic mutant type II heat-labile enterotoxin, was shown to have potent mucosal and systemic adjuvant properties. In contrast to LT-IIb, which binds strongly to ganglioside receptors decorated with either
N
-acetylneuraminic acid (NeuAc) or
N
-glycolylneuraminic acid (NeuGc), LT-IIb(T13I) binds NeuAc gangliosides much less well. Rather, LT-IIb(T13I) binds preferentially to NeuGc gangliosides. To determine if the adjuvant properties of LT-IIb(T13I) are altered in the absence of NeuGc ganglioside receptors, experiments were conducted using a
Cmah
-null mouse line which is deficient in the synthesis of NeuGc gangliosides. Several immunomodulatory properties of LT-IIb(T13I) were shown to be dependent on NeuGc gangliosides. LT-IIb(T13I) had reduced binding activity for NeuGc-deficient B cells and macrophages; binding to NeuGc-deficient T cells and dendritic cells (DC) was essentially undetectable. Treatment of
Cmah
-null macrophages with LT-IIb(T13I), however, upregulated the transcription of interleukin-4 (IL-4), IL-6, IL-17, and gamma interferon (IFN-γ), four cytokines important for promoting immune responses. The production of mucosal IgA and serum IgG against an immunizing antigen was augmented in NeuGc-deficient mice administered LT-IIb(T13I) as a mucosal adjuvant. Notably, NeuGc gangliosides are not expressed in humans. Still, treatment of human monocytes with LT-IIb(T13I) induced the secretion of IL-6, an inflammatory cytokine that mediates differential control of leukocyte activation. These results suggested that NeuAc gangliosides are sufficient to mediate the immunomodulatory properties of LT-IIb(T13I) in mice and in human cells. The nontoxic mutant enterotoxin LT-IIb(T13I), therefore, is potentially a new and safe human mucosal adjuvant.
Rapid, Simple, Quantitative, and Highly Sensitive Antibody Detection for Lyme Disease
Authors: Burbelo Peter D. , Issa Alexandra T. , Ching Kathryn H. , Cohen Jeffrey I. , Iadarola Michael J. , Marques Adriana
Published: April 2010

There is currently a need for improved serological tests for the diagnosis and monitoring of Lyme disease, an infection caused byBorrelia burgdorferi. In the present study, we evaluated luciferase immunoprecipitation systems (LIPSs) for use for profiling of the antibody responses to a panel ofB. burgdorferiproteins for the diagnosis of Lyme disease. Initially, serum samples from a cohort of patients and controls (n= 46) were used for training and were profiled by the use of 15 differentB. burgdorferiantigen constructs. For the patient sera, the antibody responses to severalB. burgdorferiantigens, including VlsE, flagellin (FlaB), BmpA, DbpA, and DbpB, indicated that the antigens had high levels of immunoreactivity. However, the best diagnostic performance was achieved with a synthetic protein, designated VOVO, consisting of a repeated antigenic peptide sequence, VlsE-OspC-VlsE-OspC, Analysis of an independent set of serum samples (n= 139) used for validation showed that the VOVO LIPS test had 98% sensitivity (95% confidence interval [CI], 93% to 100%;P< 0.0001) and 100% specificity (95% CI, 94% to 100%;P< 0.0001). Similarly, the C6 peptide enzyme-linked immunosorbent assay (ELISA) also had 98% sensitivity (95% CI, 93% to 100%;P< 0.0001) and 98% specificity (95% CI, 90% to 100%;P< 0.0001). Receiver operating characteristic analysis revealed that the rates of detection of Lyme disease by the LIPS test and the C6 ELISA were not statistically different. However, the VOVO LIPS test displayed a wide dynamic range of antibody detection spanning over 10,000-fold without the need for serum dilution. These results suggest that screening by the LIPS test with VOVO and otherB. burgdorferiantigens offers an efficient quantitative approach for evaluation of the antibody responses in patients with Lyme disease.
Molecular Evidence of Perinatal Transmission of
Bartonella vinsonii
subsp.
berkhoffii
and
Bartonella henselae
to a Child
Authors: Breitschwerdt Edward B. , Maggi Ricardo G. , Farmer Peter , Mascarelli Patricia E.
Published: April 2010

Bartonella vinsonii
subsp.
berkhoffii
,
Bartonella henselae
, or DNA of both organisms was amplified and sequenced from blood, enrichment blood cultures, or autopsy tissues from four family members. Historical and microbiological results support perinatal transmission of
Bartonella
species in this family. It is of clinical relevance that
Bartonella
spp. may adversely influence human reproductive performance.
Cardiac Tamponade and Heart Failure Due to Myopericarditis as a Presentation of Infection with the Pandemic H1N1 2009 Influenza A Virus
Authors: Puzelli Simona , Buonaguro Franco M. , Facchini Marzia , Palmieri Annapina , Calzoletti Laura , De Marco Maria A. , Arace Pasquale , de Campora Enrico , Esposito Ciro , Cassone Antonio , Rezza Giovanni , Donatelli Isabella
Published: April 2010

We describe a fatal case of myopericarditis presenting with cardiac tamponade in a previously healthy 11-year-old child. Pandemic H1N1 2009 influenza A virus sequences were identified in throat and myocardial tissues and pericardial fluid, suggesting damage of myocardial cells directly caused by the virus.
Improving Molecular Detection of Fungal DNA in Formalin-Fixed Paraffin-Embedded Tissues: Comparison of Five Tissue DNA Extraction Methods Using Panfungal PCR
Authors: Muñoz-Cadavid C. , Rudd S. , Zaki S. R. , Patel M. , Moser S. A. , Brandt M. E. , Gómez B. L.
Published: April 2010

DNA extraction from formalin-fixed paraffin-embedded (FFPE) tissues is difficult and requires special protocols in order to extract small amounts of DNA suitable for amplification. Most described methods report an amplification success rate between 60 and 80%; therefore, there is a need to improve molecular detection and identification of fungi in FFPE tissue. Eighty-one archived FFPE tissues with a positive Gomori methenamine silver (GMS) stain were evaluated using five different commercial DNA extraction kits with some modifications. Three different panfungal PCR assays were used to detect fungal DNA, and two housekeeping genes were used to assess the presence of amplifiable DNA and to detect PCR inhibitors. The sensitivities of the five extraction protocols were compared, and the quality of DNA detection (calculated for each kit as the number of housekeeping gene PCR-positive samples divided by the total number of samples) was 60 to 91% among the five protocols. The efficiencies of the three different panfungals used (calculated as the number of panfungal-PCR-positive samples divided by the number of housekeeping gene PCR-positive samples) were 58 to 93%. The panfungal PCR using internal transcribed spacer 3 (ITS3) and ITS4 primers yielded a product in most FFPE tissues. Two of the five DNA extraction kits (from TaKaRa and Qiagen) showed similar and promising results. However, one method (TaKaRa) could extract fungal DNA from 69 of the 74 FFPE tissues from which a housekeeping gene could be amplified and was also cost-effective, with a nonlaborious protocol. Factors such as sensitivity, cost, and labor will help guide the selection of the most appropriate method for the needs of each laboratory.