bluuebunny/crossref_metadata_2025 huggingface dataset:
CHANGES IN LISTERIA MONOCYTOGENES INDUCED BY ORIGANUM VULGARE L. and ROSMARINUS OFFICINALIS L. ESSENTIAL OILS ALONE AND COMBINED AT SUBINHIBITORY AMOUNTS
Authors: DE AZERÊDO GEÍZA ALVES , DE FIGUEIREDO REGINA CELIA BRESSAN QUEIROZ , DE SOUZA EVANDRO LEITE , STAMFORD TÂNIA LÚCIA MONTENEGRO
Published: April 2012

This study aimed to evaluate the antibacterial activities of the essential oils from Origanum vulgare L. and Rosmarinus officinalis L., both singly and in combination at subinhibitory concentrations against Listeria monocytogenes, and to investigate the possible mechanisms underlying these activities. Used singly or in a mixture, the essential oils led to a significant decrease in cell viability during 24 h of exposure. Decreased glucose consumption and the loss of cellular material by L. monocytogenes were found immediately after addition of the essential oils alone and in combination, and continued for up to 360 min. Analysis of cells exposed to the essential oils using electron microscopy revealed drastic ultrastructural changes occurring over time, including the changes in cell wall structure, rupture of plasma membranes, shrinking of the cytoplasmic content and leakage of intracellular material. O. vulgare L. and R. officinalis L. essential oils combined at subinhibitory concentrations could be rationally applied to inhibit the growth of L. monocytogenes in food products.

PRACTICAL APPLICATIONS

L. monocytogenes is a foodborne pathogen of particular concern in ready‐to‐eat products, such as minimally processed vegetables, because of its ability to survive and grow at refrigeration temperatures. The special risk posed by L. monocytogenes for the consumption of minimally processed vegetables has led to investigations on the development of novel technologies to control this contamination. In this context, plant essential oils have received particular interest for their potential to control L. monocytogenes in these foods. The findings of our study clearly indicate that the essential oil of oregano and rosemary, singly or in combination at subinhibitory concentrations, caused critical damages in L. monocytogenes cells. These essential oils combined at subinhibitory concentrations could be rationally applied to control the survival of L. monocytogenes in foods.
EFFECT OF STORAGE AT 4 AND 10C ON THE GROWTH OF LISTERIA MONOCYTOGENES IN AND ON QUESO FRESCO*
Authors: LEGGETT L.N. , TOMASULA P.M. , VAN HEKKEN D.L. , PORTO‐FETT A.C.S. , SHOYER B. , RENYE J.A. , LUCHANSKY J.B. , FARKYE N.
Published: April 2012

A five‐strain rifampicin‐resistant Listeria monocytogenes cocktail (ca. 3.0 log10 cfu/g) was introduced as a postpasteurization contaminant in queso fresco (QF) that was manufactured using a commercial procedure. L. monocytogenes was either inoculated into (IN) the curds before forming the cheese block or onto (ON) slices (52–66 g), individually vacuum‐packed and stored at 4 and 10C. Growth was monitored for up to 35 days. Gompertz analyses showed small differences in lag time because of temperature, but growth rate and generation time were faster at 10C than at 4C. After 20 days for both the IN and the ON treatments, the maximum population density was 7.80 ± 0.17, regardless of the storage temperature. These results indicate that QF manufacture must be conducted using Good Manufacturing Practices and under hygienic conditions, and that the use of antimicrobials and/or postprocessing interventions is necessary to prevent the presence and growth of L. monocytogenes.

PRACTICAL APPLICATIONS

Queso fresco (QF) is a popular, rennet‐set, Hispanic‐style fresh cheese made from pasteurized milk known for its crumbly texture and nonmelting properties. However, its high moisture content, near neutral pH and moderate salt content provide the ideal conditions for growth of various spoilage and pathogenic bacteria, notably Listeria monocytogenes. Past studies have examined the growth of L. monocytogenes on QF but were typically conducted using retail cheese of unknown manufacturing, handling and storage procedures. In this study, the growth of L. monocytogenes was monitored in and on QF made according to a commercial procedure used in the U.S.A. These data and a primary model that was created from the data can be used as the basis for food safety assessments and process and formulation improvements, or to monitor the effectiveness of antimicrobials and process interventions in preventing the presence and growth of L. monocytogenes associated with QF.
USE OF GRAM‐NEGATIVE MEDIUM AND IMMUNOMAGNETIC SEPARATIVE METHOD FOLLOWED BY MULTIPLEX POLYMERASE CHAIN REACTION FOR THE DETECTION OF ENTEROHEMORRHAGIC ESCHERICHIA COLI AND SALMONELLA SPP. WITH GREAT CELL COUNT DIFFERENCE IN FOOD SAMPLES
Authors: TSAI CHENG‐CHIH , HSIH HSIEN‐YEE , TSAI CHENG‐HSIEN , TSEN HAU‐YANG
Published: April 2012

Contamination of different bacterial species with great cell count difference in food samples may affect the efficacy of multiplex polymerase chain reaction (mPCR) detection of these organisms. The purpose of this study was to improve the efficiency of mPCR detection of two pathogenic bacterial species, i.e., Salmonella and Shiga‐like toxin I Escherichia coli (SLTI EC), with great cell count difference in food samples. Without the enrichment step, when the cell count ratio of these two species was higher than 103, the bacteria presenting the lower number might go undetectable. For beef and milk samples with great ratios of SLTI EC/Salmonella, such as 103–105/100–101, if gram‐negative (GN) broth was used for the pre‐enrichment step, both organisms were detectable by mPCR. However, for samples with great ratios of Salmonella/SLTI EC, after enrichment with GN broth, an immunomagnetic separation (IMS) step using equimolar mixture of anti‐Salmonella and anti‐enterohemorrhagic Escherichia coli immunobeads had to be performed prior to mPCR to allow obvious results for both organisms. Therefore, although GN is a selective medium for both Salmonella and E. coli, depending on the ratios of the two target organisms in food samples, an IMS step may be required to allow the simultaneous PCR detection of both organisms.

PRACTICAL APPLICATIONS

Although multiplex polymerase chain reaction (mPCR) method allows the simultaneous detection of different target organisms, if the ratios of the cell counts for these target organisms were great, the PCR results for target organisms with lower counts will be obscured. Using gram‐negative broth for pre‐enrichment followed by mPCR or pre‐enrichment and immunomagnetic separation (IMS) followed by mPCR, we were able to simultaneously detect enterohemorrhagic Escherichia coli and Salmonella in food samples even the cell count ratios of these two organisms were great. Similar approach could be used for the simultaneous detection of two or more bacterial species in different samples.
Tapping Supplier Innovation
Authors: Wagner Stephan M.
Published: April 2012

Tapping supplier innovation necessitates the effective management of the “fuzzy front end” of the new product development (NPD) process. This study considers the role of suppliers in the fuzzy front end and the influence of supplier integration on the focal firm'sNPDoutcomes. Project‐level data with multiple informants indicate a strong positive relationship between supplier integration in the fuzzy front end and NPD project performance. Furthermore, relationship‐specific assets and supplier integration in the firm'sNPDprocess moderate this relationship.
The Kozeny‐Carman Equation with a Percolation Threshold
Authors: Porter Lee B. , Ritzi Robert W. , Mastera Lawrence J. , Dominic David F. , Ghanbarian‐Alavijeh Behzad
Published: April 2012

A procedure has been developed for calculating permeability (k) from the Kozeny‐Carman equation, a procedure that links ideas from percolation theory with the ideas ofKoltermann and Gorelick (1995)andEsselburn et al. (2011). The approach focuses on the proportion of coarser pores that are occupied by finer sediments relative to a percolation threshold proportion (ωc). If the proportion occupied is belowωc, then the unoccupied coarser pores percolate. Otherwise they do not percolate. Following the ideas ofKoltermann and Gorelick (1995), the effective grain‐size term in the Kozeny‐Carman equation is calculated using the geometric mean if the unoccupied coarse pores percolate, and using the harmonic mean if otherwise. Following ideas ofEsselburn et al. (2011), this approach is implemented by evaluating the potential for grains in each size category to occupy pores among sediment of each larger‐size category. Application of these ideas to physical sediment models for sands and gravels, which have knownk, indicates that a threshold does indeed exist. Results also suggest that the Kozeny‐Carman equation is robust and gives representative values fork, even thoughωcis not precisely known.
MEASURING THE THREAT OF GLOBAL CRIME: INSIGHTS FROM RESEARCH BY THE LEAGUE OF NATIONS INTO THE TRAFFIC IN WOMEN*
Authors: KNEPPER PAUL
Published: April 2012

Despite increasing concern about the threat of global crime, it remains difficult to measure. During the 1920s and 1930s, the League of Nations conducted the first social‐scientific study of global crime in two studies of the worldwide traffic in women. The first study included 112 cities and 28 countries; researchers carried out 6,500 interviews in 14 languages, including 5,000 with figures in the international underworld. By drawing on archival materials in Geneva and New York, this article examines the role of ethnography in developing a social‐science measure of global crime threats. The discussion covers the Rockefeller grand jury and formation of the Bureau of Social Hygiene; the League's research in Europe, the Americas, and the Mediterranean; controversy concerning the use of undercover researchers; the League's research in Asia; and the end of the Bureau. The League's experience demonstrates the promise of multisite ethnography in research about global crime as well as the difficulty of mapping crime on a global scale.
Endocannabinoids modulate non‐adrenergic, non‐cholinergic inhibitory neurotransmission in strips from the mouse gastric fundus
Authors: Garella R. , Baccari M. C.
Published: April 2012

Aim

To investigate the effects of endocannabinoids on non‐adrenergic, non‐cholinergic (NANC) relaxant responses in gastric strips from mice.

Methods

Gastric longitudinal strips from the fundus region were mounted in organ baths for isometric recording.

Results

In carbachol‐precontracted strips, electrical field stimulation (EFS) elicited tetrodotoxin (TTX)‐sensitive fast nitrergic relaxant responses that were followed, at the highest stimulation frequency, by sustained relaxations. The latter were abolished by α‐chymotrypsin. Anandamide caused a TTX‐sensitive relaxation that was abolished by α‐chymotrypsin but unaffected by the nitric oxide (NO) synthesis inhibitor, Nω‐nitro‐L‐arginine (L‐NNA). Anandamide reduced the amplitude of EFS‐induced fast relaxations, whereas increased that of sustained ones. Relaxation to the nicotinic receptor agonist dimethylphenyl piperazinium iodide (DMPP) was decreased in amplitude by either anandamide or L‐NNA, whereas, surprisingly, it was increased by α‐chymotrypsin and abolished by L‐NNA plus α‐chymotrypsin. Relaxation to vasoactive intestinal polypeptide (VIP) was not influenced by anandamide or L‐NNA and was abolished by α‐chymotrypsin. Following VIP desensitization, fast relaxant responses to EFS were reduced and the sustained ones abolished. The CB1 receptor antagonist AM251 increased, only at the highest stimulation frequency, the amplitude of the EFS‐induced fast relaxation and reduced the sustained one. AM251 increased the response to DMPP and abolished that to anandamide. The CB2 receptor antagonist AM630 had no effects.

Conclusion

These results indicate that endocannabinoids modulate, via prejunctional CB1 receptors, the NANC peptidergic neurotransmission that, in turn, affects the nitrergic one.
Properties of an Alkaline‐Tolerant, Thermostable Xylanase from Streptomyces chartreusis L1105, Suitable for Xylooligosaccharide Production
Authors: Zhu Yunping , Li Xiuting , Sun Baoguo , Song Huanlu , Li E , Song Hongxia
Published: April 2012

Abstract:  An extracellular xylanase was purified to homogeneity from a culture of Streptomyces chartreusis L1105 by a 2‐step method of ammonium sulfate precipitation and carboxymethyl sepharose fast‐flow chromatography (CMSFF). The xylanase was purified by 6.86‐fold, with a recovery yield of 31.96%. The purified xylanase appeared as a single protein band on SDS‐PAGE with a molecular mass of about 34.2 kDa. The optimum temperature and pH of the purified xylanase activity were 70 °C and 7.2 respectively. The xylanase was more stable under alkaline conditions and retained more than 80% activity after 30 min incubation at pH 6 to 10. It also showed specific activity towards different xylans. Hydrolysis of oat‐spelt and corn‐cob xylans by the xylanase yielded xylobiose and xylotriose as principle products without the formation of xylose. These properties indicate that the purified xylanase may potentially be useful in biotechnological applications, such as xylooligosaccharide preparation. This is the first report about the purification and characterization of a xylanase from S. chartreusis.
Microbial Activity Inhibition in Chilled Mackerel (Scomber Scombrus) by Employment of an Organic Acid‐Icing System
Authors: Sanjuás‐Rey Minia , Gallardo José M. , Barros‐Velázquez Jorge , Aubourg Santiago P.
Published: April 2012

Abstract:  The present study concerns Atlantic mackerel (Scomber scombrus) traded as a chilled product. The study was aimed to investigate the effect of including a mixture of organic acids (citric, ascorbic, and lactic) in the icing medium employed during the fish chilled storage. To this end and according to preliminary trials results, an aqueous solution including 0.050% (w/v) of each acid was employed as icing medium; its effect on the microbial activity development in mackerel muscle was monitored for up to 13 d of chilled storage and compared to a counterpart‐fish batch kept under traditional water ice considered as control. Results indicated a lower bacterial growth in mackerel muscle subjected to storage in the organic acid‐icing system by comparison with control fish. Thus, statistically‐significant (P < 0.05) differences between both batches for all 6 microbial groups investigated (aerobes, anaerobes, psychrotrophes, Enterobacteriaceae, lipolytics, and proteolytics) and for 2 chemical indices related to microbial activity development (total volatile bases and trimethylamine) were obtained. The surface wash caused by the melting of the ice during storage and the subsequent antimicrobial effect of such acids on skin microflora of the fish can be invoked as the main reasons for the limited bacterial growth found in the corresponding mackerel muscle.

Practical Application:  Among natural antioxidants, citric, ascorbic, and lactic acids are low molecular weight organic compounds that represent a relevant choice because of their easy availability, low commercial cost, and wide range of permitted concentrations for their use in foods. Present results obtained by their inclusion in a novel icing system have led to a lower microbial development in chilled mackerel when compared to its counterpart fish kept under traditional icing conditions. Such a finding indicated that inclusion of this acid mixture in the icing medium can lead to a marked quality and safety enhancement as well as to profitable commercial value increases.
Effects of Enzymatic Hydrolysis of Protein on the Pasting Properties of Different Types of Wheat Flour
Authors: Chen J.S. , Wang S.Y. , Deng Z.Y. , Zhang X.Y. , Feng S.L. , Yuan H.Q. , Tian J.C
Published: April 2012

Abstract:  As one of the most effective methods to modify proteins, enzymatic hydrolysis is used widely in the preparation of wheat products in the food industry. During the same process, starch pasting occurs frequently. The effects of wheat protein hydrolysis with papain, pepsin, and trypsin on the pasting properties of 3 different kinds of flour were investigated in 5 concentrations. Results showed that the peak viscosity, trough, final, and integral area of pasting curve of these flours decreased with increasing enzymatic hydrolysis of protein, and decreased significantly with the increasing enzyme concentrations. Medium‐gluten flour was the least sensitive to enzymatic activity and weak‐gluten the most sensitive. Downtrends appeared with increasing papain and trypsin concentrations in the form of breakdown. Enzymes had no significant different effect on the peak times of strong‐ and medium‐gluten flour, but prolonged peak time slightly in weak‐gluten flour. The pasting time and temperature of strong‐ and medium‐gluten flour were significantly increased in a concentration‐dependent manner. However, there were no significant effects on the pasting times of weak‐gluten flour. These results could supply a basis for utilization of enzymatic hydrolysis of wheat protein in food industry and for further studies into the interactions between hydrolyzed protein and starch in food or processing industries.

Practical Application:  Illuminating the effects of enzymatic hydrolysis of protein on the pasting properties of different types of wheat flour is very important in food industry. Flour viscosity decreases after enzymatic hydrolysis of protein/gluten. Enzymes have different effects on peak time, pasting time, and pasting temperatures for different types of flour. These results could supply a basis for utilization of enzymatic hydrolysis of wheat protein in food industry and for further studies into the interactions between hydrolyzed protein and starch in food or processing industries.
Rapid Tomato Volatile Profiling by Using Proton‐Transfer Reaction Mass Spectrometry (PTR‐MS)
Authors: Farneti Brian , Cristescu Simona M. , Costa Guglielmo , Harren Frans J.M. , Woltering Ernst J.
Published: April 2012

Abstract:  The availability of rapid and accurate methods to assess fruit flavor is of utmost importance to support quality control especially in the breeding phase. Breeders need more information and analytical tools to facilitate selection for complex multigenic traits such as flavor quality. In this study, it is shown that proton‐transfer reaction mass spectrometry (PTR‐MS) is a suitable method to monitor at high sensitivity the emission of volatiles determining the tomato aromatic profile such as hexanal, hexenals, methanol, ethanol, and acetaldehyde. The volatiles emitted by 14 tomato varieties (at red stage) were analyzed by 2 solvent‐free headspace methods: solid‐phase microextraction/gas chromatography MS and PTR‐MS. Multivariate statistics (principal component analysis and cluster analysis) of the PTR‐MS results allow an unambiguous separation between varieties, especially with a clear fingerprinting separation between the different tomato types: round truss, cocktail, and cherry tomatoes. PTR‐MS was also successfully used to monitor the changes in volatile profiles during postharvest ripening and storage.

Practical Application:  These results show that proton‐transfer reaction mass spectrometry (PTR‐MS) is suited to monitor at high sensitivity the emission of a large number of volatiles that describe the tomato aroma profile. This technology can easily monitor and quantify compounds related to ripening and/or senescence so that it can be used to improve the breeding of new fruit and vegetable cultivars based on volatiles. Moreover, PTR‐MS can be used to monitor changes in volatile profile during ripening and storage.
Suspected tick paralysis (Ixodes holocyclus) in a Miniature Horse
Authors: Tee SY , Feary DJ
Published: April 2012

A 9‐year‐old Miniature Horse gelding infested with ticks (Ixodes holocyclus) was presented with flaccid motor paralysis causing recumbency. Neurological examination and other diagnostic tests did not identify an alternative aetiology, leading to a presumptive diagnosis of tick paralysis. The gelding was treated with tick antiserum and intensive supportive care. He made a gradual recovery over the 48 h following presentation and was discharged without further complications. This case report describes in detail the clinical signs and successful treatment of a Miniature Horse with flaccid paralysis caused by suspected envenomation by Ixodes holocyclus.
Comparison of the use of cabergoline and gonadotrophin to treat primary and secondary anoestrus in bitches
Authors: Nak D , Nak Y , Simsek G
Published: April 2012

Objective  To determine the efficacy and reliability of cabergoline and pregnant mare's serum gonadotrophin (PMSG) for induction of oestrus in bitches with primary or secondary anoestrus.

Procedures  We studied 39 healthy bitches of various breeds aged 2–6 years and in primary or secondary anoestrus: 20 bitches were administered 5 µg/kg/day cabergoline orally until day 2 after the onset of pro‐oestrus or for a maximum of 42 days, and 19 bitches were administered 20 IU/kg/day PMSG intramuscularly for 5 consecutive days, followed by an additional single injection of 25 IU/kg of human chorionic gonadotrophin on the fifth day.

Results  The rates of oestrus induction in the primary and secondary anoestrous bitches treated with cabergoline and PMSG were found to be similar. Pregnancy and whelping rates in the cabergoline group were statistically different from the rates in the PMSG group (P < 0.001).

Conclusion  Cabergoline is more effective and reliable for the induction of a fertile oestrus in bitches with primary or secondary anoestrous.
Prevalence of breech‐strike in mulesed, clipped and unmulesed Merino hoggets in south‐eastern Australia
Authors: Larsen JWA , Tyrell LD , Anderson N
Published: April 2012

Objective  To compare the prevalence of breech flystrike (‘breech‐strike’) on 12–20‐month‐old Merino hoggets that were mulesed, had breech and tail clips applied (‘clipped’) or were left unmulesed but treated strategically with long‐acting insecticide.

Design  A cohort study on three farms in southern Victoria.

Methods  Three treatment groups were established at lamb marking on each farm. The unmulesed group was treated with dicyclanil when 12 months old in September or October (‘early‐season treatment’). The prevalence of breech‐strike and key risk factors, including soiling of the breech with faeces (‘dag’) and urine (‘stain’), and breech wrinkle, were compared between the groups.

Results  Over all the farms, breech‐strike occurred on 1.1% of mulesed sheep and 7.7% of clipped sheep. Clipped sheep had a relative risk of breech‐strike of 18.2‐, 16.8‐ and 3.0‐fold that of mulesed sheep on the three farms. Unmulesed sheep treated with dicyclanil had a similar prevalence of breech‐strike to that of mulesed sheep (overall 0.9%, range 0–2.5%), but had significantly more dag, stain and wrinkle.

Conclusion  Early‐season treatment of unmulesed sheep prevented most breech‐strikes during the spring and early summer, and offers a short‐ to medium‐term option for the control of breech‐strike in south‐eastern Australia. There were some benefits associated with using clips, namely less dag and stain, and a shorter time spent crutching. However, to control breech‐strike the clipped sheep should be treated the same as unmulesed sheep. Reducing the prevalence and severity of dag will be a major component of strategies to control breech‐strike of Merinos in this region.
TLR2 and TLR4 Gene Expression in Peripheral Monocytes in Nondiabetic Hypertensive Patients: The Effect of Intensive Blood Pressure–Lowering
Authors: Marketou Maria E. , Kontaraki Joanna E. , Zacharis Evangelos A. , Kochiadakis George E. , Giaouzaki Aikaterini , Chlouverakis Gregory , Vardas Panos E.
Published: April 2012

J Clin Hypertens (Greenwich). 2012; 14:330–335. ©2012 Wiley Periodicals, Inc.

The activation of innate immune receptors, such as Toll‐like receptors (TLRs), participates in the pathogenesis of cardiovascular diseases. The authors evaluated TLR2 and TLR4 gene expression in the peripheral monocytes of nondiabetic hypertensive patients compared with normotensive individuals and investigated the effect of intensive systolic blood pressure (SBP)–lowering. Included were 43 nondiabetic hypertensive patients with essential hypertension who were randomly assigned to an intensive treatment arm, with an SBP target of <130 mm Hg, or a standard arm, with an SBP target of <140 mm Hg. TLR2 and TLR4 messenger RNA (mRNA) levels in monocytes were estimated before and 12 weeks after therapy initiation. Sixteen healthy individuals were included for comparison. Hypertensives revealed significantly higher TLR4 mRNA levels compared with normotensives (985±885 vs 554±234, P=.005). In contrast, no statistically significant difference was found in TLR2. Compared with standard treatment, intensive treatment significantly downregulated TLR2 and TLR4 mRNAs, expressed as fold induction (0.66±0.49 vs 1.38±1.65 and 0.62±0.3 vs 1.9±1.2, respectively; P<.001 for both). In conclusion, TLR4 mRNA levels in peripheral monocytes are significantly elevated in nondiabetic hypertensive patients. Intensive control of SBP results in attenuation of TLR2 and TLR4 gene expression in those patients. Our findings suggest that a strict SBP target in nondiabetic hypertensive patients may offer additional benefits.
Conservation genetics and evolution in an endangered species: research in Sonoran topminnows*
Authors: Hedrick Philip W. , Hurt Carla R.
Published: April 2012

Conservation genetics of endangered species has primarily focused on using neutral markers to determine units of conservation and estimating evolutionary parameters. Because the endangered Sonoran topminnow can be bred in the laboratory and has a relatively short generation length, experiments to examine both detrimental and adaptive variations are also possible. Here, we discuss over two decades of empirical and experimental observations in the Sonoran topminnow. Results from this research have been used to determine species and evolutionary significant units using neutral markers, document inbreeding and outbreeding depression and genetic load using experimental crosses, and measure adaptive differences in fitness‐related traits and variation in pathogen resistance among populations and major histocompatibility complex genotypes. In addition, both premating and postmating reproductive isolation between Gila and Yaqui topminnows have been experimentally determined, and the predicted and observed ancestry of these two species in experimental crosses has been examined over time. Although some have suggested that endangered species are unsuitable for experimentation because of both practical and ethical considerations, these results demonstrate that in this case an endangered species can be employed to examine fundamental questions in conservation and evolution.
Evolution of critical day length for diapause induction enables range expansion of Diorhabda carinulata, a biological control agent against tamarisk (Tamarix spp.)
Authors: Bean Dan W. , Dalin Peter , Dudley Tom L.
Published: April 2012

In classical weed biological control, small collections of arthropods are made from one or a few sites in the native range of the target plant and are introduced to suppress the plant where it has become invasive, often across a wide geographic range. Ecological mismatches in the new range are likely, and success using the biocontrol agent may depend on postrelease evolution of beneficial life history traits. In this study, we measure the evolution of critical day length for diapause induction (day length at which 50% of the population enters dormancy), in a beetle (Diorhabda carinulata) introduced into North America from China to control an exotic shrub, Tamarix spp. Beetle populations were sampled from four sites in North America 7 years after introduction, and critical day length was shown to have declined, forming a cline over a latitudinal gradient At one field site, decreased critical day length was correlated with 16 additional days of reproductive activity, resulting in a closer match between beetle life history and the phenology of Tamarix. These findings indicate an enhanced efficacy and an increasingly wider range for D. carinulata in Tamarix control.
Caries prevalence, severity, and 3‐year increment, and their impact upon New Zealand adolescents' oral‐health‐related quality of life
Authors: Foster Page Lyndie A. , Thomson W. Murray
Published: April 2012

Objective: To examine dental caries experience among New Zealand adolescents and determine the nature of caries‐associated differences in oral‐health‐related quality of life (OHRQoL) among adolescents.

Method: Follow‐up was conducted of a random sample of 430 children first examined in 2003 at age 13, when they completed the Child Perceptions Questionnaire (CPQ11‐14). At age 16, 255 (59.3% of the baseline sample) were re‐examined and again completed the CPQ11‐14.

Results: Caries prevalence (1 + DMFS) rose from 68% to 79.2%; mean DMFS rose from 2.9 (SD 4.7) to 3.6 (SD 4.8), and the prevalence of high caries experience (5 + DMFS) rose from 20.0% to 40.8%. The 3‐year mean net caries increment of 0.5 surfaces (SD 2.6) was dominated by occlusal surfaces. At both ages, overall CPQ11‐14 scores, as well as emotional well‐being subscale scores, were significantly higher for those with DMFS values of 5 or more.

Conclusion: Caries experience increased over the three years; this age group is caries‐active. Dental caries affects adolescents' OHRQoL, although not as strongly as maybe expected.
Visualization of blood drainage area from hypervascular hepatocellular carcinoma on ultrasonographic images during hepatic arteriogram: Comparison with depiction of drainage area on contrast‐enhanced ultrasound
Authors: Kita Ryuichi , Sakamoto Azusa , Nagata Yoshiaki , Nishijima Norihiro , Ikeda Atsuyuki , Matsuo Hiroo , Okada Mitsumasa , Ashida Shinji , Taniguchi Toshikatsu , Kimura Toru , Osaki Yukio
Published: April 2012

Aim:  Corona enhancement is the visualized drainage area from a hypervascular tumor observed on single‐level dynamic computed tomography during hepatic arteriography (CTHA) and is thought to be a high‐risk area for micrometastases. However, because it cannot be visualized with ordinary ultrasonography (US), we aimed to visualize corona enhancement on US by means of arterial injection of the contrast material and to measure its thickness.

Method:  Forty‐one hypervascular hepatocellular carcinoma (HCC) cases were prospectively investigated. US during hepatic arteriography (USHA) was executed by means of selective injection of the contrast material perfluorobutane (Sonazoid) from the hepatic artery. Ordinary contrast‐enhanced US with venous administration of contrast material and single‐level dynamic CTHA were also performed.

Results:  Corona enhancement was observed in 36 cases (88%) on USHA and in 25 cases (61%) on single‐level dynamic CTHA. The thickness of corona enhancement of 36 cases visualized with USHA ranged 3.1–18.4 mm and the mean thickness ± standard deviation was 6.0 ± 3.0 mm. Thickness of corona enhancement was less than 10.0 mm in 34 cases (94%).

Conclusion:  Corona enhancement could be visualized even on US images, and the average thickness of them was 6 mm.
Prognostic factors in patients with idiopathic portal hypertension: Two Japanese nationwide epidemiological surveys in 1999 and 2005
Authors: Murai Yoko , Ohfuji Satoko , Fukushima Wakaba , Tamakoshi Akiko , Yamaguchi Shohei , Hashizume Makoto , Moriyasu Fuminori , Hirota Yoshio
Published: April 2012

Aim:  To investigate factors affecting disease prognosis among patients with idiopathic portal hypertension (IPH).

Methods:  Two Japanese nationwide epidemiological surveys on IPH were conducted in 1999 and 2005. Analyzing data from each cross‐sectional survey separately, we examined the consistent prognostic factors detected from each analysis and assessed the effect of treatments for varices on IPH prognosis. Outcome was the disease condition at last observation compared with that at diagnosis, categorized into two levels (recovered/improved and unchanged/aggravated/deceased). To evaluate the association with each characteristic, we calculated adjusted odds ratio (OR) and 95% confidence interval (CI) using a binary model for logistic regression.

Results:  Among 160 patients with IPH in 1999 and 85 in 2005, 10% had aggravated disease at a mean of 6–7 years after the diagnosis. Statistically significant ORs were observed for two factors: esophageal varices, especially of F2–3 stage, at diagnosis (OR = 6.83, 95% CI = 2.10–22.1 in 1999; OR = 10.7, 95% CI = 1.08–105 in 2005) ameliorated IPH; and hepatic encephalopathy at diagnosis (OR = 0.19, 95% CI = 0.03–1.04 in 1999; crude OR = 0.05, 95% CI = 0.01–0.60 in 2005 using a proportional odds model) worsened IPH. Further analyses explained that the apparent ameliorating effect of esophageal varices was due to the effect of subsequent treatment (OR = 4.59, 95% CI = 0.89–23.7 in 2005).

Conclusion:  The prognosis of IPH would be better if varices were adequately controlled. Patients with liver failure at diagnosis would be at high risk for subsequent disease aggravation.
The Impact of Corporate Governance on the Relationship between Investment Opportunities and Dividend Policy: An Endogenous Switching Model Approach*
Authors: Lin Kun‐Li , Shen Chung‐Hua
Published: April 2012

This study investigates the role of corporate governance in the relationship between investment opportunities and dividend payouts. The study sample is divided into strong and weak governance regimes to investigate outcome and substitute effects, where the former stresses the negative relationship between investment opportunity and dividend payouts in a strong governance regime while the latter emphasizes the positive relationship between the two in a weak governance regime. Using the endogenous switching model on a sample of Taiwan publicly listed firms from 2000 to 2009, this study concludes that the substitute model hypothesis is supported using different governance variables, but no outcome effect is identified.
Market Reactions to the Split‐share Structure Reform and the Determinants of Compensation: Evidence from Chinese Listed Firms
Authors: Cheng Li , Chiou Jeng‐Ren , Chen Yenn‐Ru , Lee Bong Soo
Published: April 2012

The split‐share structure is a unique characteristic of corporate ownership in China, and is often linked to poor firm performance and inefficient corporate governance. In this paper, we investigate market reactions around several important event days during the process of the split‐share structure reform (share reform) in Chinese listed firms. The market reacts differently to different events during the process. First, the market reacts positively to firms’ intention of implementing the share reform when the reform prospectus is disclosed and when the compensation is actually paid. Second, after the reform is actually implemented, the market reacts negatively when the expiration date of the lockup agreement is announced, because the restricted trading shares can be freely traded and thus share supply increases after the expiration date. In addition, the compensation paid to tradable shareholders by non‐tradable shareholders is determined by the stock liquidity before the reform, the proportion of restricted trading shares, and the type of ultimate shareholders. We further find that the payment of compensation, the proportion of restricted shares after the share reform, and a time gap between suspension and resumption days are the main factors affecting the market reaction.
Is There a Relationship Between Corporate Governance and Value‐based Financial Performance Measures? A Study of Turkey as an Emerging Market
Authors: Bayrakdaroglu Ali , Ersoy Ersan , Citak Levent
Published: April 2012

The purpose of this study is to investigate the relationship of value‐based performance measures – economic value added (EVA), market value added (MVA) and cash value added (CVA) – with corporate governance using data on 41 corporations listed on the Istanbul Stock Exchange‐100 Index. Multiple panel regression is used covering the 1998–2007 period. The findings indicate that EVA, MVA, and CVA increase if the CEO is a member of the board at the same time, and board size does not significantly affect performance. Ownership concentration is significantly related to all performance measures except for MVA, while manager ownership is not a significant variable in increasing corporate performance. Foreign ownership is found to increase EVA but decrease MVA.
Long-term stability of quercetin nanocrystals prepared by different methods
Authors: Kakran Mitali , Shegokar Ranjita , Sahoo Nanda Gopal , Gohla Sven , Li Lin , Müller Rainer H
Published: April 2012

Objectives

This study aimed to examine the long-term physical stability of quercetin nanocrystals produced by three methods.

Methods

Quercetin nanocrystals were prepared by high pressure homogenization, bead milling and cavi-precipitation. The nanocrystals produced by these methods were compared for particle size, saturation solubility and dissolution of the drug particles, and were subjected to stability testing.

Key findings

The X-ray diffraction study and microscopic pictures taken under polarized light indicated the crystalline nature of the nanocrystals produced by the three methods. As the crystalline state is relatively more stable than the amorphous state, a good physical stability was expected from the quercetin nanocrystals prepared. The high-pressure homogenized and bead-milled quercetin nanocrystals showed excellent physical stability when stored under refrigeration (4 ± 2°C) and at room temperature (25 ± 2°C) for 180 days. The dissolution properties were not significantly affected on storage at room temperature. However, increase in the storage temperature to 40 ± 2°C led to physical instability. On the other hand, the cavi-precipitated quercetin nanocrystals exhibited a lower stability than the bead-milled and homogenized formulations and did not show the optimum zeta potential values as well. In the case of cavi-precipitated nanocrystals, recrystallization and agglomeration were responsible for the increasing particle size besides the Ostwald ripening phenomenon. The solvents used during cavi-precipitation might have competed with the surfactant for hydration leading to a partial dehydration of the surfactant, which subsequently affected the stability of the quercetin nanocrystals.

Conclusions

High-pressure homogenized and bead-milled quercetin nanocrystals showed better physical stability than the cavi-precipitated ones. Freeze drying immediately after nanocrystal production can help to prevent their agglomeration and thus improve physical stability.
The stopping criteria for mirror‐gazing in body dysmorphic disorder
Authors: Baldock Emma , Anson Martin , Veale David
Published: April 2012

Objectives. To investigate whether prolonged compulsive mirror‐gazing in body dysmorphic disorder (BDD) is characterized by the prioritization of internally referenced (internal) goals for the mirror session, such as feeling right about one's make‐up or shaven face, over externally referenced (external) goals, such as seeing that one's make‐up is applied, or seeing that there is no more stubble on one's face.

Design. Cross‐sectional case control.

Methods. Twenty‐one participants with BDD and 18 community controls (CCs) recalled a recent mirror session in a semi‐structured interview and then completed the Mirror‐Gazing Goals and Terminating Factors Questionnaire (MGGTFQ), an instrument developed for the present study.

Results. Internal goals were rated as more important in the BDD group than the CC group, but there was no difference between groups in the importance of external goals. The BDD group identified internal goals significantly more frequently than the CC group among their three most important goals. The BDD group reported significantly lower achievement ratings for the three most important goals and were more likely to terminate the session for reasons unrelated to their goals (e.g., frustration). For all participants, the importance of internal goals was positively correlated with the length of the mirror session.

Conclusions. The findings support current recommendations for targeting internal goals in interventions for problematic mirror use. Limitations and future directions are discussed, including the need to establish whether the use of internal goals is causally related to the length of the mirror session.

Practitioner points

BDD patients prioritize internal goals defined by feeling states when they look in the mirror (e.g., they aim above all to feel right about their make‐up or shaven face), and then tend not to achieve their goals and end the mirror session for reasons unrelated to their goals (e.g., distress or time constraints).

Educating patients about these potentially problematic ‘internal’ goals, and encouraging them to aim for alternative goals (e.g., a fixed length of time, or an external goal defined by visual cues) might help patients to reduce the time they spend looking in the mirror.

The study is limited by the correlational design, the reliance on retrospective reporting, and the lack of a clinical control group.
An investigation of different aspects of overgeneralization in patients with major depressive disorder and borderline personality disorder
Authors: van den Heuvel Thom J. , Derksen Jan J. L. , Eling Paul A. T. M. , van der Staak Cees P. F.
Published: April 2012

Objective. The aim of this study was to investigate whether (a) overgeneralization is restricted to negative attributions directed at the self; or whether it also extends to positive self‐attributions and to attributions of situations in the outside world, and (b) whether the valence and direction (positively or negatively, to the self‐ or across situations) of overgeneralization processes vary among different patient populations.

Methods. Patients with major depressive disorder (MDD, n = 34), borderline personality disorder (BPD, n = 18), or both (n = 35), and never‐depressed non‐patients (NPs; n = 50) completed various measures of overgeneralization.

Results. Patients with MDD show higher levels of negative overgeneralization but lower levels of positive overgeneralization to the self‐ and across situations than NPs. Patients with MDD show more negative than positive overgeneralization to the self: a negative bias. They, however, do show higher levels of positive than negative overgeneralization across situations. Patients with BPD show the same pattern for overgeneralization to the self, but their higher levels of negative overgeneralization across situations are not exceeded by their positive counterpart.

Conclusions. Results indicate that patient groups differ from NPs not only with respect to negative, but also with respect to positive overgeneralization. Furthermore, the valence and direction of overgeneralization processes vary among MDD and BPD patient populations. More specifically, findings suggest that, as compared to never‐depressed individuals, patients with BPD and patients with MDD alike, lack a buffer against negative overgeneralization directed at the self. In patients with BPD, not only the high level of overgeneralization to the self, but also the high level of overgeneralization across situations seems to be problematic, since both types of overgeneralization appear not to be buffered by their positive counterparts.
Bilayer graphene by bonding CVD graphene to epitaxial graphene
Authors: Jernigan Glenn G. , Anderson Travis J. , Robinson Jeremy T. , Caldwell Joshua D. , Culbertson Jim C. , Myers-Ward Rachael , Davidson Anthony L. , Ancona Mario G. , Wheeler Virginia D. , Nyakiti Luke O. , Friedman Adam L. , Campbell Paul M. , Kurt Gaskill D.
Published: April 2012

A novel method for creating bilayer graphene is described where single-layer CVD graphene grown on Cu is bonded to single-layer epitaxial graphene grown on Si-face SiC. Raman microscopy and x ray photoelectron spectroscopy demonstrate the uniqueness of this bilayer, as compared to a naturally formed bilayer, in that a Bernal stack is not formed with each layer being strained differently yet being closely coupled. Electrical characterization of Hall devices fabricated on the unusual bilayer show higher mobilities, and lower carrier concentrations, than the individual CVD graphene or epitaxial graphene layers.
Using online telescopes to explore exoplanets from the physics classroom
Authors: Gould Roy R. , Sunbury Susan , Krumhansl Ruth
Published: April 2012

The search for habitable planets offers excellent opportunities to advance students’ understanding of core ideas in physics, including gravity and the laws of motion, the interaction of light and matter, and especially the nature of scientific inquiry. Thanks to the development of online telescopes, students can detect more than a dozen of the known exoplanets from the classroom, using data they gather, assess, and interpret for themselves. We present a suite of activities in which students apply basic physics concepts to their investigations of exoplanets. The activities were developed and successfully tested with physics and earth science teachers in secondary schools in 14 states. Included are additional challenges and assessments suitable for introductory college physics courses.
Trajectories of charged particles trapped in Earth’s magnetic field
Authors: Öztürk M. Kaan
Published: April 2012

This article presents the theory of relativistic charged-particle motion in Earth’s magnetosphere, at a level suitable for undergraduate courses. I discuss particle and guiding center motion and derive the three adiabatic invariants associated with the three periodic motions in a dipolar field. I provide 12 computational exercises that can be used as classroom assignments or for self-study. Two of the exercises, drift-shell bifurcation and Speiser orbits, are adapted from active magnetospheric research. The PYTHON code provided in the supplement can be used to replicate the trajectories and can be easily extended for different field geometries.
A robotic observatory in the city
Authors: Ruch Gerald T. , Johnston Martin E.
Published: April 2012

The University of St. Thomas (UST) Observatory is an educational facility integrated into UST’s undergraduate curriculum as well as the curriculum of several local schools. Three characteristics combine to make the observatory unique. First, the telescope is tied directly to the support structure of a four-story parking ramp instead of an isolated pier. Second, the facility can be operated remotely over an Internet connection and is capable of performing observations without a human operator. Third, the facility is located on campus in the heart of a metropolitan area where light pollution is severe. Our tests indicate that, despite the lack of an isolated pier, vibrations from the ramp do not degrade the image quality at the telescope. The remote capability facilitates long and frequent observing sessions and allows others to use the facility without traveling to UST. Even with the high background due to city lights, the sensitivity and photometric accuracy of the system are sufficient to fulfill our pedagogical goals and to perform a variety of scientific investigations. In this paper, we outline our educational mission, provide a detailed description of the observatory, and discuss its performance characteristics.