bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantitative trait loci mapping and stability for low temperature germination ability of rice
Authors: Ji S. L. , Jiang L. , Wang Y. H. , Zhang W. W. , Liu X. , Liu S. J. , Chen L. M. , Zhai H. Q. , Wan J. M.
Published: June 2009

A high rate of germination at low temperatures is necessary for economic yields to be maintained. In this paper, the genetic control of low temperature germination ability (LTG) was assessed by the measurement of germination rate (GR), germination rate index (GI) and mean germination time (MGT), and genetically mapped using a set of recombinant inbred lines, derived from a cross between the japonica cultivar ‘Asominori’ and the indica cultivar ‘IR24’. Putative quantitative trait loci (QTL) were validated by testing in two related sets of chromosome segment substitution lines (CSSL). In this genetic background, LTG is under the control of a number of QTL, each of relatively small effect, and is spread over six chromosomes. The most stable of these QTL was for GR, mapping to a segment of chromosome 11 which also carries a QTL for GI. On chromosome 2, qGR‐2 not only controlled GR, but also was associated with GI and MGT. Significant differences in LTG were detected between ‘Asominori’ and some CSSL harbouring qGR‐2 or qGR‐11.
Home telehealth for diabetes management: a systematic review and meta‐analysis
Authors: Polisena J. , Tran K. , Cimon K. , Hutton B. , McGill S. , Palmer K.
Published: June 2009

Aim: It is estimated that more than 180 million people worldwide have diabetes. Health‐care providers can remotely deliver health services to this patient population using information and communication technology, also known as home telehealth. Home telehealth may be classified into two subtypes: home telemonitoring (HTM) and telephone support (TS). The research objective was to systematically review the literature and perform meta‐analyses to assess the potential benefits of home telehealth compared with usual care (UC) for patients with diabetes.

Methods: An electronic literature search was conducted to identify studies on home telehealth and patients with diabetes that were published between 1998 and 2008 using Medline, Medline In‐Process & Other Non‐Indexed Citations, BIOSIS Previews and EMBASE.

Results: Twenty‐six studies (n = 5069 patients) on home telehealth for diabetes were selected. Twenty‐one studies evaluated HTM and 5 randomized controlled trials assessed TS. HTM had a positive effect on glycaemic control [as measured by lower glycated haemoglobin level] compared with UC (weighted mean difference =−0.21; 95% confidence interval −0.35 to −0.08), but the results were mixed for TS. Study results indicated that home telehealth helps to reduce the number of patients hospitalized, hospitalizations and bed days of care. Home telehealth was similar or favourable to UC across studies for quality‐of‐life and patient satisfaction outcomes.

Conclusions: In general, home telehealth had a positive impact on the use of numerous health services and glycaemic control. More studies of higher methodological quality are required to give more precise insights into the potential clinical effectiveness of home telehealth interventions.
Perspectives of UK Vice‐Chancellors on Leading Universities in a Knowledge‐Based Economy
Authors: Bosetti Lynn , Walker Keith
Published: June 2009

This paper draws upon the experiences and perceptions of ten university vice‐chancellors in the United Kingdom on the challenges they face in providing leadership and strategic direction for their institutions into the twenty‐first century. The paper reveals the perceptions and spoken words of these leaders as they identify the key challenges shaping higher education, their strategies for addressing these challenges, their struggle to maintain the core mission of universities and finally, implications for the future of higher education.
‘What’s the Next Stage?’ Mothers of Young Adults with Down Syndrome Explore the Path to Independence: A Qualitative Investigation
Authors: Docherty Julie , Reid Kate
Published: June 2009

Background An increased life expectancy for young adults with Down syndrome has coincided with legislative changes to improve access to housing and employment. This study explores the values and beliefs of mothers of young adults with Down syndrome currently involved in supporting their offspring in the possible transition from dependence to independence.

Methods Eight mothers of young adults with Down syndrome were interviewed and the results were thematically analysed using the qualitative approach, Interpretative Phenomenological Analysis (IPA).

Result The mothers described themselves as having a dynamic role as both gate‐keepers and facilitators in aiding their offspring on the path to adulthood.

Conclusions These findings are not consistent with findings of previous research, which suggested that mothers in this situation are personally and socially inclined to limit the transition of their offspring to an independent adulthood. The discussion explores the possible reasons for this change and proposes clarification to existing theoretical frameworks for understanding mothers’ perspectives. Limitations of the research and future recommendations are discussed.
Consumer‐Directed Goal Planning in the Delivery of Assistive Technology Services for People who are Ageing with Intellectual Disabilities
Authors: Mirza Mansha , Hammel Joy
Published: June 2009

Background  A consumer‐directed service‐delivery approach to assistive technology and environmental modification intervention was examined with people who were ageing with intellectual disabilities.

Material and Methods  The intervention was based on a collaborative approach involving consumers, their social supports and service deliverers. Thirty individuals were randomly selected to receive the intervention from a sample of 75 community‐dwelling adults. Outcomes related to consumers’ and significant others’ perceptions of performance and satisfaction with goal attainment were assessed and the consumer‐directed goal planning process examined.

Results  Participants in the intervention group reported significantly higher levels of performance and satisfaction related to goals identified at baseline than participants in the control group. Two broad categories of goals were addressed during the intervention – basic self‐care goals and participation/environmental/systems level goals. A 98% direct agreement rate between consumer‐identified goals and goals addressed by service deliverers was found during the intervention. Of the environmental strategies employed during the intervention, assistive devices and systems level advocacy and action were the two most frequently used across goals.

Conclusion  Results provide evidence in favour of a consumer‐directed approach to assistive technology and environmental modification service delivery for consumers who are ageing with intellectual disabilities.
Organisation of obstetric services for very preterm births in Europe: results from the MOSAIC project
Authors: Blondel B , Papiernik E , Delmas D , Künzel W , Weber T , Maier RF , Kollée L , Zeitlin J ,   the Mosaic Research Group
Published: June 2009

Objective  To study the impact of the organisation of obstetric services on the regionalisation of care for very preterm births.

Design  Cohort study.

Setting  Ten European regions covering 490 000 live births.

Population  All children born in 2003 between 24 and 31 weeks of gestation.

Method  The rate of specialised maternity units per 10 000 total births, the proportion of total births in specialised units and the proportion of very preterm births by referral status in specialised units were compared.

Main outcome measure  Birth in a specialised maternity unit (level III unit or unit with a large neonatal unit (at least 50 annual very preterm admissions).

Results  The organisation of obstetric care varied in these regions with respect to the supply of level III units (from 2.3 per 10 000 births in the Portuguese region to 0.2 in the Polish region), their characteristics (annual number of deliveries, 24 hour presence of a trained obstetrician) and the proportion of all births (term and preterm) that occur in these units. The proportion of very preterm births in level III units ranged from 93 to 63% in the regions. Different approaches were used to obtain a high level of regionalisation: high proportions of total deliveries in specialised units, high proportions of in utero transfers or high proportions of high‐risk women who were referred to a specialised unit during pregnancy.

Conclusion  Consensus does not exist on the optimal characteristics of specialised units but regionalisation may be achieved in different models of organisation of obstetric services.
Resilience, Restoration, and Riparian Ecosystems: Case Study of a Dryland, Urban River
Authors: White Jacqueline M. , Stromberg Juliet C.
Published: June 2009

Resilient systems can absorb disturbance and persist despite variability as long as the capacity of the system to adapt is not exceeded. Riparian plant communities of dryland alluvial rivers are expected to be naturally resilient systems because they persist in the highly variable floodplain. River modification has altered the flow regime on many dryland rivers, in some cases exceeding the adaptive capacity of the riparian vegetation, but these changes may be readily reversible. The Salt River in Phoenix, Arizona has been impounded, dewatered, channelized, but also re‐watered with urban effluent and storm drain runoff. To determine whether riparian vegetation is resilient to these various perturbations, paired comparisons were made in the vegetation and seed bank between a non‐diverted reference reach, a diverted reach, and a re‐watered urban reach. In the diverted reach, composition had shifted to that of a stress tolerant xeroriparian shrubland with low diversity in both the seed bank and extant vegetation. Most surprisingly, few differences were observed in the composition and structure of the vegetation and soil seed banks between the reference reach and the urban reach, particularly in the wet patches, suggesting that hydric riparian plant communities have the capacity to adapt to these modified conditions. These results provide support for a process‐oriented approach to restoration on the Salt River and other urban dryland rivers using patches of persisting vegetation as models for achievable restoration targets.
Isolated Trees and Grass Removal Improve Performance of Transplanted Trema micrantha (L.) Blume (Ulmaceae) Saplings in Tropical Pastures
Authors: García‐Orth Ximena , Martínez‐Ramos Miguel
Published: June 2009

Cattle pastures established in areas previously covered by tropical rainforest can be abandoned in unproductive and degraded conditions. Transplanting native tree species to pastures is one common practice among rainforest restoration techniques, but several environmental barriers compromise transplant success. We assessed whether the presence of isolated trees and the removal of pasture grasses affect survival, growth, and allometry of transplanted saplings of the pioneer tree Trema micrantha (L.) Blume (Ulmaceae) into abandoned pastures in southeast Mexico. An isolated tree was selected in the center of each of four pasture sites of one hectare, and grass treatments were applied under the tree's canopy (0–10 m from the trunk) and in open pasture (15–48 m from the trunk). Grass removal treatments were control (grass present), cut with machete, herbicide application, and total grass removal with a gardening hoe. After 1 year, sapling survival was not different between the canopy and pasture areas (53%). Saplings showed higher survival probability (p < 0.05) in the hoe treatment (63 ± 9%) than in the control treatment (38 ± 9%). Height and crown cover growth rates were faster under the canopy of isolated trees compared with the open pasture. Saplings showed significantly greater crown area/height ratios under the canopy of isolated trees. Stressful environmental conditions restricted sapling growth in the open pasture. We conclude that complete removal of grasses and transplanting T. micrantha saplings in the vicinity of isolated trees can improve transplant success.
Evaluation of Right Ventricular Function by Using Tissue Doppler Imaging in Patients after Repair of Tetralogy of Fallot
Authors: Çetin İlker , Tokel Kürşad , Varan Birgül , Örün Utku , Aşlamaci Sait
Published: June 2009

Background: The aim of this study was to assess the relation between plasma B‐type natriuretic peptide (BNP) levels and right ventricular function evaluated by tissue Doppler imaging (TDI) in patients after repair of tetralogy of Fallot (ToF). Methods: Twenty‐five patients with a mean age of 14.1 ± 4.4 years who underwent repair of ToF at a mean age of 4.9 ± 5.1 years enrolled in this study. The control group consisted of 29 healthy children at a mean age of 13.1 ± 2.8 years. The right ventricle and pulmonary regurgitation (PR) were assessed by two‐dimensional echocardiography and color Doppler. Blood samples for BNP levels were taken and TDI was performed at rest. Results: Plasma BNP levels were significantly higher in patients than in controls (28.3 ± 24.1 vs. 7.4 ± 2.3 pg/mL, P = 0.0001). The myocardial performance index (MPI) (1.08 ± 0.35 vs. 0.58 ± 0.11, P = 0.0001) was higher and isovolumic acceleration (IVA) (3.1 ± 0.7 vs. 5.4 ± 1.0 m/s2, P = 0.0001) was lower in patients. The correlations were also significant between the degree of PR and MPI (r = 0.7, P = 0.0001) and also IVA (r =−0.7, P = 0.0001). The correlations were also significant between the BNP level and MPI (r = 0.6, P = 0.0001), IVA (r =−0.4, P = 0.002) and the degree of PR (r = 0.6, P = 0.0001). Conclusion: As a result, plasma BNP level increases in patients with ToF and both MPI and IVA from the right ventricular basal segments might be used to assess the right ventricular function.
Tei Index Correlates with Tissue Doppler Parameters and Reflects Neurohormonal Activation in Patients with an Abnormal Transmitral Flow Pattern
Authors: Greco Stefania , Troisi Federica , Brunetti Natale Daniele , Di Biase Matteo
Published: June 2009

Background: Tei index (TI) is a Doppler parameter which reflects combined systolic and diastolic function. We aimed to study the relationship between TI, both traditional and tissue Doppler imaging (TDI) echocardiographic parameters and neurohormonal profile in outpatients with diastolic dysfunction expressed by an abnormal transmitral flow pattern. Methods and Results: A total of 67 consecutive outpatients with diastolic dysfunction (abnormal transmitral flow pattern) were studied; all patients underwent clinical evaluation, blood sampling for B‐type natriuretic peptide (BNP) plasma assaying, echocardiography for the determination of left ventricular ejection fraction (LVEF), dP/dt, left atrium (LA) dimensions, longitudinal systolic (S) and diastolic wall velocities (E′and A′), TI measured with Doppler echocardiography, and mitral regurgitation (MR) quantified on a semicontinuous scale. TI values were significantly correlated with BNP levels (r = 0.33; P < 0.01), LVEF (r =−0.56; P < 0.001), dP/dt (r =−0.52; P < 0.01), S (r =−0.45; P < 0.001), E′(r =−0.36; P < 0.01), A′(r =−0.27; P < 0.05), LA volume (r = 0.35; P < 0.01), and MR (P for trend < 0.05). In a multivariate regression analysis, TI was an independent predictor of increased BNP levels (β= 0.32; P < 0.05), even after correction for potential confounders. ROC analysis showed as values of TI >0.59 identified subjects with combined systolic and diastolic dysfunction with a sensitivity of 73.8% and a specificity of 71.4%. Conclusions: In outpatients with diastolic dysfunction, TI, an easy to perform parameter for global ventricular performance assessment, might be useful in identifying subjects with concomitant systolic impairment and neurohormonal activation.
Intima‐Media Thickness and Flow‐Mediated Vasodilation in Asymptomatic Subjects with Newly Detected Severe Hypercholesterolemia
Authors: Vladimirova‐Kitova Lyudmila , Terzieva Dora , Marinov Blagoi
Published: June 2009

Background: The aim was to establish the predictors of early functional and structural vascular alterations (using intima‐media thickness (IMT)) and flow‐mediated vasodilation (%FMD) as well as to investigate the interrelationship between IMT and %FMD in asymptomatic, never‐treated, severe hypercholesterolemia (HH). Methods: One hundred and twenty patients with asymptomatic, severe, untreated HH and 100 controls were included. ELISA was used for asymmetric dimethylarginine (ADMA) and cellular adhesion molecules, and fluid chromatography for total homocysteine (tHcy). Hewlett Packard SONOS 5500 with a 7.5 MHz transducer and MedicaSoft IMT software were used for evaluation of %FMD and IMT of common carotid artery (CCA). Results: Patients and controls differ with respect to all tested biomarkers (P < 0.05), except for P‐selectin and E‐selectin (P < 0.05). %FMD was lower in patients (P < 0.001). The IMT of the CCA was higher in patients (P < 0.001). Inverse correlations were found between %FMD and IMT mean and age, ADMA, Apo‐B, Apo‐B/Apo‐A1, and tHcy. ADMA was established as the most important factor related to %FMD. Age and Apo‐B were established as the most important factors related to IMT mean. An inverse correlation was established between %FMD and IMT mean (rxy= 0.546; P < 0.001)). If cases with IMT mean ≥1 were excluded, the correlation weakened. In patients with IMT mean ≥1 mm, the correlation did not change. Conclusion: In conclusion, asymptomatic, untreated patients with severe hypercholesterolemia are at high risk of having increased IMT of the CCA, especially if there is endothelial dysfunction, verified by %FMD of the brachial artery.
Macro‐ and micro‐anatomical, histological and computed tomography scan characterization of the nasopalatine canal
Authors: Liang Xin , Jacobs Reinhilde , Martens Wendy , Hu YuQian , Adriaensens Peter , Quirynen Marc , Lambrichts Ivo
Published: June 2009

Aim: To determine the human anatomic variability of the nasopalatine canal and determine its characteristics using an anatomical, histological and computed tomography (CT) scan evaluation.

Materials and Methods: Measurements for the canal characteristics were carried out on 163 dry human skulls and 120 upper jaw spiral CT scans, taken from patients for pre‐operative planning purposes of implant placement in the incisor region. Furthermore, four human cadaver specimens were imaged using a high‐resolution magnetic resonance imaging (HR‐MRI) unit. Afterwards, these specimens were serially sectioned for histological examination to evaluate the nasopalatine canal region and its content.

Results: The nasopalatine canal anatomy showed a large variability in morphology and dimensions, with the canal branching in up to four canals at the level of the nose. The canal diameter was on average 3.3 mm (±0.9 mm SD), and typically enlarged by age and male gender (p<0.05). HR‐MRI and histological sections enabled to identify the neurovascular structures within the canals.

Conclusions: The large anatomic variations, the increased canal dimensions with age and the neurovascular canal content are all factors favouring a thorough three‐dimensional planning before surgery, such as implant placement, of the anterior maxillary region.
Risk factors for atherosclerosis in cases with severe periodontitis
Authors: Buhlin Kåre , Hultin Margareta , Norderyd Ola , Persson Lena , Pockley Alan Graham , Rabe Per , Klinge Björn , Gustafsson Anders
Published: June 2009

Aim: Studies have reported on an association between cardiovascular disease (CVD) and periodontitis. The purpose of this case–control study was to provide an insight into this association by determining the plasma levels of some risk markers for CVD in cases with periodontitis.

Materials and Methods: Sixty‐eight cases with periodontitis, mean age 53.9 (SD 7.9) years, and 48 randomly selected healthy controls, mean age 53.1 (SD 7.9) years, were investigated. Fasting blood plasma was analysed for glucose, lipids, markers systemic inflammation, cytokines and antibodies against heat shock proteins (Hsp). The associations between periodontitis and the various substances analysed in plasma were calculated using a multivariate logistic regression model, which compensated for age, gender, smoking and body mass index.

Results: The regression analyses revealed a significant association between periodontitis and high levels of C‐reactive protein (CRP) [odds ratio (OR) 4.0, confidence interval (CI) 1.4–11.4] and fibrinogen (OR 8.7, CI 2.6–28.4), IL‐18 (OR 6.5, CI 2.2–19.5), and decreased levels of IL‐4 (OR 0.12, CI 0.0–0.5). The study showed increased levels of antibodies against Hsp65 (OR 2.8, CI 1–7.6) and 70 (OR 2.9, CI 1.1–7.8) and decreased levels of antibodies against Hsp60 (OR 0.3, CI 0.1–0.8).

Conclusions: Periodontitis was associated with increased levels of CRP, glucose, fibrinogen and IL‐18, and with decreased levels of IL‐4.
X‐ray crystal structures of Phanerochaete chrysosporium Laminarinase 16A in complex with products from lichenin and laminarin hydrolysis
Authors: Vasur Jonas , Kawai Rie , Andersson Evalena , Igarashi Kiyohiko , Sandgren Mats , Samejima Masahiro , Ståhlberg Jerry
Published: June 2009

The 1,3(4)‐β‐d‐glucanases of glycoside hydrolase family 16 provide useful examples of versatile yet specific protein–carbohydrate interactions. In the present study, we report the X‐ray structures of the 1,3(4)‐β‐d‐glucanase Phanerochaete chrysosporium Laminarinase 16A in complex with β‐glucan products from laminarin (1.6 Å) and lichenin (1.1 Å) hydrolysis. The G6G3G3G glucan, in complex with the enzyme, showed a β‐1,6 branch in the acceptor site. The G4G3G ligand–protein complex showed that there was no room for a β‐1,6 branch in the −1 or −2 subsites; furthermore, the distorted residue in the −1 subsite and the glucose in the −2 subsite required a β‐1,3 bond between them. These are the first X‐ray crystal structures of any 1,3(4)‐β‐d‐glucanase in complex with glucan products. They provide details of both substrate and product binding in support of earlier enzymatic evidence.
Recent Advances in Intravesical Treatment of Overactive Bladder
Authors: KUO Hann‐Chorng
Published: June 2009

The traditional medication for overactive bladder (OAB) is antimuscarinic agent, which targets muscarinic receptors. Recent investigations have revealed that muscarinic receptors are present in the urothelium and suburothelial sensory fibers, as well as in the detrusor. Urothelial dysfunction and abnormality of sensory receptor expression or transmitter release in suburothelial nerves could contribute to OAB refractory to antimuscarinics. Intravesical treatment to inhibit abnormal receptor expression or transmitter release in the sensory nerve terminals in the suburothelial space might provide beneficial therapeutic effects in the treatment of OAB. Intravesical resiniferatoxin (RTX) instillation and intravesical botulinum toxin A (BoNT‐A) injection are two promising treatment alternatives for refractory OAB. RTX at a high dose may cause undesired adverse events, such as hematuria, bladder pain or autonomic dysreflexia. RTX at a low concentration can decrease sensory urgency without influencing detrusor contractility; multiple instillations of low‐dose RTX may be required to achieve adequate desensitization of OAB. BoNT‐A, however, has a beneficial effect on detrusor contractility and causes large post‐void residual after injection in some patients. Therefore, careful dosage and injection site adjustment is mandatory to achieve satisfactory results using intravesical therapy.
Relationship between Blood Pressure and Nocturia in Hypertensive Patients
Authors: SUGAYA Kimio , NAKADA Seiguo , SIMOJI Tsutomu , ODAGUCHI Naoyuki , NAKAMOTO Minori , NAKAZATO Satoshi
Published: June 2009

Objective: We investigated the relationship between the pattern of hypertension and nocturia.

Methods: Seventy‐seven patients who were being treated for hypertension completed a questionnaire regarding the number of times they urinated during the day and at night, and measured their blood pressure at home immediately after rising in the morning and just before going to sleep at night. The patients' blood pressure was also measured at the clinic. The patients were divided into groups according to their blood pressure patterns. The relationship between blood pressure pattern and number of urinations during the day and at night was investigated.

Results: When the patients were divided into white coat hypertension, masked hypertension, sustained hypertension, and normotension groups, the number of daytime urinations was significantly lower in the sustained hypertension group compared with the normotension and white coat hypertension groups. When the subjects were divided into morning blood pressure surge and non‐morning surge groups or into morning hypertension and non‐morning hypertension groups, the numbers of nighttime urinations was significantly higher in the morning surge group or the morning hypertension group compared with the non‐morning surge group or non‐morning hypertension group, respectively.

Conclusion: Sustained hypertension and elevation of blood pressure in the early morning influence the frequency of daytime and nighttime urination, respectively. It is important to control both the blood pressure and nocturia of hypertensive patients to improve their prognosis.
Low‐level laser irradiation promotes the recovery of atrophied gastrocnemius skeletal muscle in rats
Authors: Nakano Jiro , Kataoka Hideki , Sakamoto Jyunya , Origuchi Tomoki , Okita Minoru , Yoshimura Toshiro
Published: June 2009

Low‐level laser (LLL) irradiation promotes proliferation of muscle satellite cells, angiogenesis and expression of growth factors. Satellite cells, angiogenesis and growth factors play important roles in the regeneration of muscle. The objective of this study was to examine the effect of LLL irradiation on rat gastrocnemius muscle recovering from disuse muscle atrophy. Eight‐week‐old rats were subjected to hindlimb suspension for 2 weeks, after which they were released and recovered. During the recovery period, rats underwent daily LLL irradiation (Ga–Al–As laser; 830 nm; 60 mW; total, 180 s) to the right gastrocnemius muscle through the skin. The untreated left gastrocnemius muscle served as the control. In conjunction with LLL irradiation, 5‐bromo‐2′‐deoxyuridine (BrdU) was injected subcutaneously to label the nuclei of proliferating cells. After 2 weeks, myofibre diameters of irradiated muscle increased in comparison with those of untreated muscle, but did not recover back to normal levels. Additionally, in the superficial region of the irradiated muscle, the number of capillaries and fibroblast growth factor levels exhibited significant elevation relative to those of untreated muscle. In the deep region of irradiated muscle, BrdU‐positive nuclei of satellite cells and/or myofibres increased significantly relative to those of the untreated muscle. The results of this study suggest that LLL irradiation can promote recovery from disuse muscle atrophy in association with proliferation of satellite cells and angiogenesis.
Slow Viscous Flow in a Syringe
Authors: Watson L. T. , Billups S. C. , Wang C.-Y. , Everett E. A.
Published: June 2009

The slow viscous flow in a syringe is modeled by the quasi-steady axisymmetric Stokes equation with a point sink for the needle hole. The governing equations are approximated using nonstandard finite difference formulas optimized for the boundary conditions, and solved numerically using a SOR technique. Streamlines and pressure profiles are computed for a variety of syringe configurations.
Heat Transport Mechanisms in Vascular Tissues: A Model Comparison
Authors: Baish J. W. , Ayyaswamy P. S. , Foster K. R.
Published: June 2009

We have conducted a parametric comparison of three different vascular models for describing heat transport in tissue. Analytical and numerical methods were used to predict the gross temperature distribution throughout the tissue and the small-scale temperature gradients associated with thermally significant blood vessels. The models are: 1) an array of unidirectional vessels, 2) an array of countercurrent vessels, and 3) a set of large vessels feeding small vessels which then drain into large vessels. We show that three continuum formulations of bioheat transfer (directed perfusion, effective conductivity, and a temperature-dependent heat sink) are limiting cases of the vascular models with respect to the thermal equilibration length of the vessels. When this length is comparable to the width of the heated region of tissue, the local temperature changes near the vessels can be comparable to the gross temperature elevation. These results are important to the use of thermal techniques used to measure the blood perfusion rate and in the treatment of cancer with local hyperthermia.
Adherence of
Escherichia coli
O157:H7 Mutants In Vitro and in Ligated Pig Intestines
Authors: Yin Xianhua , Chambers James R. , Wheatcroft Roger , Johnson Roger P. , Zhu Jing , Liu Bianfang , Gyles Carlton L.
Published: June 2009

There are contradictory literature reports on the role of verotoxin (VT) in adherence of enterohemorrhagic
Escherichia coli
O157:H7 (O157 EHEC) to intestinal epithelium. There are reports that putative virulence genes of O island 7 (OI-7), OI-15, and OI-48 of this pathogen may also affect adherence in vitro. Therefore, mutants of
vt2
and segments of OI-7 and genes
aidA
15
(gene from OI-15) and
aidA
48
(gene from OI-48) were generated and evaluated for adherence in vitro to cultured human HEp-2 and porcine jejunal epithelial (IPEC-J2) cells and in vivo to enterocytes in pig ileal loops. VT2-negative mutants showed significant decreases in adherence to both HEp-2 and IPEC-J2 cells and to enterocytes in pig ileal loops; complementation only partially restored VT2 production but fully restored the adherence to the wild-type level on cultured cells. Deletion of OI-7 and
aidA
48
had no effect on adherence, whereas deletion of
aidA
15
resulted in a significant decrease in adherence in pig ileal loops but not to the cultured cells. This investigation supports the findings that VT2 plays a role in adherence, shows that results obtained in adherence of
E. coli
O157:H7 in vivo may differ from those obtained in vitro, and identified AIDA-15 as having a role in adherence of
E. coli
O157:H7.
Respective Roles of Culturable and Viable-but-Nonculturable Cells in the Heterogeneity of
Salmonella enterica
Serovar Typhimurium Invasiveness
Authors: Passerat Julien , Got Patrice , Dukan Sam , Monfort Patrick
Published: June 2009

The existence of
Salmonella enterica
serovar Typhimurium viable-but-nonculturable (VBNC) cells is a public health concern since they could constitute unrecognized sources of infection if they retain their pathogenicity. To date, many studies have addressed the ability of
S
. Typhimurium VBNC cells to remain infectious, but their conclusions are conflicting. An assumption could explain these conflicting results. It has been proposed that infectivity could be retained only temporarily after entry into the VBNC state and that most VBNC cells generated under intense stress could exceed the stage where they are still infectious. Using a Radioselectan density gradient centrifugation technique makes it possible to increase the VBNC-cell/culturable-cell ratio without increasing the exposure to stress and, consequently, to work with a larger proportion of newly VBNC cells. Here, we observed that (i) in the stationary phase, the
S
. Typhimurium population comprised three distinct subpopulations at 10, 24, or 48 h of culture; (ii) the VBNC cells were detected at 24 and 48 h; (iii) measurement of invasion gene (
hilA
,
invF
, and
orgA
) expression demonstrated that cells are highly heterogeneous within a culturable population; and (iv) invasion assays of HeLa cells showed that culturable cells from the different subpopulations do not display the same invasiveness. The results also suggest that newly formed VBNC cells are either weakly able or not able to successfully initiate epithelial cell invasion. Finally, we propose that at entry into the stationary phase, invasiveness may be one way for populations of
S
. Typhimurium to escape stochastic alteration leading to cell death.
Gut Bacteria Are Not Required for the Insecticidal Activity of
Bacillus thuringiensis
toward the Tobacco Hornworm,
Manduca sexta
Authors: Johnston Paul R. , Crickmore Neil
Published: June 2009

It was recently proposed that gut bacteria are required for the insecticidal activity of the
Bacillus thuringiensis
-based insecticide, DiPel, toward the lepidopterans
Manduca sexta
,
Pieris rapae
,
Vanessa cardui
, and
Lymantria dispar
. Using a similar methodology, it was found that gut bacteria were not required for the toxicity of DiPel or Cry1Ac or for the synergism of an otherwise sublethal concentration of Cry1Ac toward
M. sexta
. The toxicities of DiPel and of
B. thuringiensis
HD73 Cry
−
spore/Cry1Ac synergism were attenuated by continuously exposing larvae to antibiotics before bioassays. Attenuation could be eliminated by exposing larvae to antibiotics only during the first instar without altering larval sterility. Prior antibiotic exposure did not attenuate Cry1Ac toxicity. The presence of enterococci in larval guts slowed mortality resulting from DiPel exposure and halved Cry1Ac toxicity but had little effect on
B. thuringiensis
HD73 Cry
−
spore/Cry1Ac synergism.
B. thuringiensis
Cry
−
cells killed larvae after intrahemocoelic inoculation of
M. sexta
,
Galleria mellonella
, and
Spodoptera litura
and grew rapidly in plasma from
M. sexta
,
S. litura
, and
Tenebrio molitor
. These findings suggest that gut bacteria are not required for
B. thuringiensis
insecticidal activity toward
M. sexta
but that
B. thuringiensis
lethality is reduced in larvae that are continuously exposed to antibiotics before bioassay.
LasI/R and RhlI/R Quorum Sensing in a Strain ofPseudomonas aeruginosaBeneficial to Plants
Authors: Steindler Laura , Bertani Iris , De Sordi Luisa , Schwager Stephan , Eberl Leo , Venturi Vittorio
Published: June 2009

Pseudomonas aeruginosapossesses three quorum-sensing (QS) systems which are key in the expression of a large number of genes, including many virulence factors. Most studies of QS inP. aeruginosahave been performed in clinical isolates and have therefore focused on its role in pathogenicity.P. aeruginosa, however, is regarded as a ubiquitous organism capable of colonizing many different environments and also of establishing beneficial associations with plants. In this study we examined the role of the twoN-acyl homoserine lactone systems known as RhlI/R and LasI/R in the environmental rice rhizosphere isolateP. aeruginosaPUPa3. Both the Rhl and Las systems are involved in the regulation of plant growth-promoting traits. The environmentalP. aeruginosaPUPa3 is pathogenic in two nonmammalian infection models, and only the doublelas rhlmutants are attenuated for virulence. In fact it was established that the two QS systems are not hierarchically organized and that they are both important for the colonization of the rice rhizosphere. This is an in-depth genetic and molecular study of QS in an environmentalP. aeruginosastrain and highlights several differences with QS regulation in the clinical isolate PAO1.
C-5(6) Sterol Desaturase from
Tetrahymena thermophila
: Gene Identification and Knockout, Sequence Analysis, and Comparison to Other C-5(6) Sterol Desaturases
Authors: Nusblat Alejandro D. , Najle Sebastián R. , Tomazic Mariela L. , Uttaro Antonio D. , Nudel Clara B.
Published: June 2009

The gene coding for a C-5(6) sterol desaturase in
Tetrahymena thermophila
,
DES5A
, has been identified by the knockout of the TTHERM_01194720 sequence. Macronucleus transformation was achieved by biolistic bombardment and gene replacement through phenotypic assortment, using paromomycin as the selective agent. A knockout cell line (KO270) showed a phenotype consistent with that of the
DES5A
deletion mutant. KO270 converted only 6% of the added sterol into the C-5 unsaturated derivative, while the wild type accumulated 10-fold larger amounts under similar conditions. The decreased desaturation activity is specific for the C-5(6) position of lathosterol and cholestanol; other desaturations, namely C-7(8) and C-22(23), were not affected. Analysis by reverse transcription-PCR reveals that
DES5A
is transcribed both in the presence and absence of cholestanol in wild-type cells, whereas the transcribed gene was not detected in KO270. The growth of KO270 was undistinguishable from that of the wild-type strain. Des5Ap resembles known C-5(6) sterol desaturases, displaying the three typical histidine motifs, four hydrophobic transmembrane regions, and two other highly conserved domains of unknown function. A phylogenetic analysis placed
T. thermophila's
enzyme and
Paramecium
orthologues in a cluster together with functionally characterized C-5 sterol desaturases from vertebrates, fungi, and plants, although in a different branch.
Structural Analysis of the Core Region of O-Lipopolysaccharide of
Porphyromonas gingivalis
from Mutants Defective in O-Antigen Ligase and O-Antigen Polymerase
Authors: Paramonov Nikolay A. , Aduse-Opoku Joseph , Hashim Ahmed , Rangarajan Minnie , Curtis Michael A.
Published: June 2009

Porphyromonas gingivalis
synthesizes two lipopolysaccharides (LPSs), O-LPS and A-LPS. Here, we elucidate the structure of the core oligosaccharide (OS) of O-LPS from two mutants of
P. gingivalis
W50, ΔPG1051 (WaaL, O-antigen ligase) and ΔPG1142 (O-antigen polymerase), which synthesize R-type LPS (core devoid of O antigen) and SR-type LPS (core plus one repeating unit of O antigen), respectively. Structural analyses were performed using one-dimensional and two-dimensional nuclear magnetic resonance spectroscopy in combination with composition and methylation analysis. The outer core OS of O-LPS occurs in two glycoforms: an “uncapped core,” which is devoid of O polysaccharide (O-PS), and a “capped core,” which contains the site of O-PS attachment. The inner core region lacks
l
(
d
)-
glycero
-
d
(
l
)-
manno
-heptosyl residues and is linked to the outer core via 3-deoxy-
d
-
manno
-octulosonic acid, which is attached to a glycerol residue in the outer core via a monophosphodiester bridge. The outer region of the “uncapped core” is attached to the glycerol and is composed of a linear α-(1→3)-linked
d
-Man OS containing four or five mannopyranosyl residues, one-half of which are modified by phosphoethanolamine at position 6. An amino sugar, α-
d
-allosamine, is attached to the glycerol at position 3. In the “capped core,” there is a three- to five-residue extension of α-(1→3)-linked Man residues glycosylating the outer core at the nonreducing terminal residue. β-
d
-GalNAc from the O-PS repeating unit is attached to the nonreducing terminal Man at position 3. The core OS of
P. gingivalis
O-LPS is therefore a highly unusual structure, and it is the basis for further investigation of the mechanism of assembly of the outer membrane of this important periodontal bacterium.
The Dual-Functioning Fumarate Reductase Is the Sole Succinate:Quinone Reductase in
Campylobacter jejuni
and Is Required for Full Host Colonization
Authors: Weingarten Rebecca A. , Taveirne Michael E. , Olson Jonathan W.
Published: June 2009

Campylobacter jejuni
encodes all the enzymes necessary for a complete oxidative tricarboxylic acid (TCA) cycle. Because of its inability to utilize glucose,
C. jejuni
relies exclusively on amino acids as the source of reduced carbon, and they are incorporated into central carbon metabolism. The oxidation of succinate to fumarate is a key step in the oxidative TCA cycle.
C. jejuni
encodes enzymes annotated as a fumarate reductase (Cj0408 to Cj0410) and a succinate dehydrogenase (Cj0437 to Cj0439). Null alleles in the genes encoding each enzyme were constructed. Both enzymes contributed to the total fumarate reductase activity in vitro. The
frdA
::
cat
+
strain was completely deficient in succinate dehydrogenase activity in vitro and was unable to perform whole-cell succinate-dependent respiration. The
sdhA
::
cat
+
strain exhibited wild-type levels of succinate dehydrogenase activity both in vivo and in vitro. These data indicate that Frd is the only succinate dehydrogenase in
C. jejuni
and that the protein annotated as a succinate dehydrogenase has been misannotated. The
frdA
::
cat
+
strain was also unable to grow with the characteristic wild-type biphasic growth pattern and exhibited only the first growth phase, which is marked by the consumption of aspartate, serine, and associated organic acids. Substrates consumed in the second growth phase (glutamate, proline, and associated organic acids) were not catabolized by the the
frdA
::
cat
+
strain, indicating that the oxidation of succinate is a crucial step in metabolism of these substrates. Chicken colonization trials confirmed the in vivo importance of succinate oxidation, as the
frdA
::
cat
+
strain colonized chickens at significantly lower levels than the wild type, while the
sdhA
::
cat
+
strain colonized chickens at wild-type levels.
Role of Periplasmic Chaperones and BamA (YaeT/Omp85) in Folding and Secretion of Intimin from EnteropathogenicEscherichia coliStrains
Authors: Bodelón Gustavo , Marín Elvira , Fernández Luis Ángel
Published: June 2009

Intimin is a bacterial adhesin located on the surface of enteropathogenicEscherichia coliand other related bacteria that is believed to self-translocate across the outer membrane (OM), and therefore it has been regarded as a member of the type V secretion system (T5SS), which includes classical autotransporters (ATs). However, intimin has few structural similarities to classical ATs and an opposite topology with an OM-embedded N region and a secreted C region. Since the actual secretion mechanism of intimin is unknown, we investigated intimin biogenesis by analyzing its requirement of periplasmic chaperones (DsbA, SurA, Skp, and DegP) and of OM protein BamA (YaeT/Omp85) for folding, OM insertion, and translocation. Using full-length and truncated intimin polypeptides, we demonstrate that DsbA catalyzes the formation of a disulfide bond in the D3 lectin-like domain of intimin in the periplasm, indicating that this secreted C-terminal domain is at least partially folded prior to its translocation across the OM. We also show that SurA chaperone plays the major role for periplasmic transport and folding of the N region of intimin, whereas the parallel pathway made by Skp and DegP chaperones plays a secondary role in this process. Further, we demonstrate that BamA is essential for the insertion of the N region of intimin in the OM and that the protease activity of DegP participates in the degradation of misfolded intimin. The significance of these findings for a BamA-dependent secretion mechanism of intimin is discussed in the context of T5SSs.
Novel Cellular Organization in a Gliding Mycoplasma,
Mycoplasma insons
Authors: Relich Ryan F. , Friedberg Aaron J. , Balish Mitchell F.
Published: June 2009

Mycoplasmas that are known to exhibit gliding motility possess a differentiated tip structure. This polar organelle mediates cytadherence and gliding motor activity and contains a cytoskeleton-like component that provides structural support. Here, we describe gliding motility and a unique cytoskeleton in
Mycoplasma insons
, which lacks any obviously differentiated tip structure.
A pragmatic randomised trial of stretching before and after physical activity to prevent injury and soreness
Authors: Jamtvedt Gro , Herbert Robert D , Flottorp Signe , Odgaard-Jensen Jan , Håvelsrud Kari , Barratt Alex , Mathieu Erin , Burls Amanda , Oxman Andrew D
Published: June 2009

Objective

To determine the effects of stretching before and after physical activity on risks of injury and soreness in a community population.

Design

Internet-based pragmatic randomised trial conducted between January 2008 and January 2009.

Setting

International.

Participants

A total of 2377 adults who regularly participated in physical activity.

Interventions

Participants in the stretch group were asked to perform 30 s static stretches of seven lower limb and trunk muscle groups before and after physical activity for 12 weeks. Participants in the control group were asked not to stretch.

Main outcome measurements

Participants provided weekly on-line reports of outcomes over 12 weeks. Primary outcomes were any injury to the lower limb or back, and bothersome soreness of the legs, buttocks or back. Injury to muscles, ligaments and tendons was a secondary outcome.

Results

Stretching did not produce clinically important or statistically significant reductions in all-injury risk (HR=0.97, 95% CI 0.84 to 1.13), but did reduce the risk of experiencing bothersome soreness (mean risk of bothersome soreness in a week was 24.6% in the stretch group and 32.3% in the control group; OR=0.69, 95% CI 0.59 to 0.82). Stretching reduced the risk of injuries to muscles, ligaments and tendons (incidence rate of 0.66 injuries per person-year in the stretch group and 0.88 injuries per person-year in the control group; HR=0.75, 95% CI 0.59 to 0.96).

Conclusion

Stretching before and after physical activity does not appreciably reduce all-injury risk but probably reduces the risk of some injuries, and does reduce the risk of bothersome soreness.

Trial registration

anzctr.org.au12608000044325.
Implementation of electronic locking devices for adolescents at German tobacco vending machines: intended and unintended changes of supply and demand
Authors: Schneider S , Meyer C , Yamamoto S , Solle D
Published: June 2009

Background:

Starting from 1 January 2007, electronic locking devices based on proof-of-age (via electronic cash cards or a European driving licence) were installed in approximately 500 000 vending machines across Germany to restrict the purchase of cigarettes to those over the age of 16.

Objective:

To examine changes in the number of tobacco vending machines before and after the introduction of these new measures.

Design:

The total number of commercial tobacco sources in 2 selected districts (70 000 inhabitants) in Cologne were recorded and mapped. This major German city was the ideal setting for this study as investigators were able to use existing sociogeographical data from the area. A complete inventory was compiled in autumn 2005 and 2007. A total of 780 students aged 12 to 15 were also interviewed in the study areas. The main outcome measures were quantities and locations of commercial tobacco sources.

Results:

Between 2005 and 2007 the total number of tobacco sources decreased from 315 to 277 within the study area. Although the most obvious reduction was detected in the number of outdoor vending machines (−48%), the number of indoor vending machines also decreased by 8%. Adolescents changed from vending machines to other sources for cigarettes, particularly kiosks or friends (+31% points usage rate, p<0.001; +35% points usage rate, p<0.001, respectively).

Conclusions:

Although the number of tobacco vending machines decreased, this has not had a significant impact on cigarette acquisition by underage smokers as they were able to circumvent this new security measure in several different ways.
LEPTON FLAVOR VIOLATING HIGGS DECAYS AND UNPARTICLE PHYSICS
Authors: ILTAN E. O.
Published: June 2009

We predict the branching ratios of the lepton flavor violating Higgs decays H0 → e± μ±, H0 → e± τ± and H0 → μ± τ± in the case that the lepton flavor violation is carried by the scalar unparticle mediation. We observe that their branching ratios are strongly sensitive to the unparticle scaling dimension and they can reach the values of the order of 10-4, for the heavy lepton flavor case and for the small values of the scaling dimension.