bluuebunny/crossref_metadata_2025 huggingface dataset:
Transcutaneous delivery and thermostability of a dry trivalent inactivated influenza vaccine patch
Authors: Frolov Vladimir G. , Seid Robert C. , Odutayo Olabisi , Al‐Khalili Mohammad , Yu Jianmei , Frolova Olga Y. , Vu Hong , Butler Barbara A. , Look Jee Loon , Ellingsworth Larry R. , Glenn Gregory M.
Published: March 2008

A patch containing a trivalent inactivated influenza vaccine (TIV) was prepared in a dried, stabilized formulation for transcutaneous delivery. When used in a guinea pig immunogenicity model, the dry patch was as effective as a wet TIV patch in inducing serum anti‐influenza IgG antibodies. When the dry TIV patch was administered with LT as an adjuvant, a robust immune response was obtained that was comparable with or better than an injected TIV vaccine. When stored sealed in a nitrogen‐purged foil, the dry TIV patch was stable for 12 months, as measured by HA content, under both refrigerated and room temperature conditions. Moreover, the immunological potency of the vaccine product was not affected by long‐term storage. The dry TIV patch was also thermostable against three cycles of alternating low‐to‐high temperatures of −20/25 and −20/40°C, and under short‐term temperature stress conditions. These studies indicate that the dry TIV patch product can tolerate unexpected environmental stresses that may be encountered during shipping and distribution. Because of its effectiveness in vaccine delivery and its superior thermostable characteristics, the dry TIV patch represents a major advance for needle‐free influenza vaccination.
Effect of Whey Protein Isolate–Pullulan Edible Coatings on the Quality and Shelf Life of Freshly Roasted and Freeze‐Dried Chinese Chestnut
Authors: Gounga M.E. , Xu S‐Y. , Wang Z. , Yang W.G.
Published: March 2008

ABSTRACT: Harvested chestnut is characterized by a short shelf life, exposing many Chinese producers to a storage problem as product losses are very high. The objective of this study was to develop a suitable technology to extend the shelf life of harvested chestnut fruits for commercial use. The effect of whey protein isolate–pullulan (WPI–Pul) coating on fresh‐roasted chestnuts (FRC) and roasted freeze‐dried chestnut (RFDC) quality and shelf life was studied under 2 different storage temperature (4 and 20 °C) conditions. Coatings were formed directly onto the surface of the fruits by dipping them into a film solution. SEM micrographs showed homogeneous WPI–Pul to cover the whole surface of chestnut with good adherence and perfect integrity. Moisture loss or gain, fruit quality, and shelf life were evaluated by weight loss or gain, surface color development, and visible decay during the storage period of 15 to 120 d at 4 and 20 °C, respectively. WPI–Pul coating had a low, yet significant effect on reducing moisture loss and decay incidence of FRC, hence delaying changes in their external color. The results were satisfactory when the coating was done with freeze‐drying at low temperature storage, thus improving the quality and increasing the shelf life. This provides an alternative strategy to minimize the significant losses in harvested chestnut.
High Relative Humidity In‐Package of Fresh‐Cut Fruits and Vegetables: Advantage or Disadvantage Considering Microbiological Problems and Antimicrobial Delivering Systems?
Authors: Ayala‐Zavala J.F. , Del‐Toro‐Sánchez L. , Alvarez‐Parrilla E. , González‐Aguilar G.A.
Published: March 2008

ABSTRACT: This hypothesis article states that the high relative humidity (RH) of packaged fresh‐cut fruits or vegetables that is associated with spoilage can be used as an advantageous way to deliver antimicrobial compounds using cyclodextrins (CDs) as carriers. CDs can function as antimicrobial delivery systems as they can release antioxidant and antimicrobial compounds (guest molecules) as the humidity levels increase in the headspace. Hydrophobic antimicrobial guests can be complexed with CDs due to the amphiphatic nature of the host. Then, at high RH values, due to the water–CDs interaction, host–guest interactions are weakened; consequently, the antimicrobial molecule is released and should protect the product against the microbial growth. Potential antimicrobial compounds capable of forming complexes with CDs are discussed, as well as possible applications to preserve fresh‐cut produce and future research in this area.
Effect of Biotic Elicitors on Enrichment of Antioxidant Properties and Induced Isoflavones in Soybean
Authors: Boué S.M. , Shih F.F. , Shih B.Y. , Daigle K.W. , Carter‐Wientjes C.H. , Cleveland T.E.
Published: March 2008

ABSTRACT:  The antioxidant properties of methanolic extracts from soybean obtained with germination, wounding, and application of biotic elicitors were evaluated. Also, the relationship between observed antioxidant properties and compositional changes in isoflavone content was determined. The 2 biotic elicitors used in this study were the food‐grade fungus Aspergillus sojae and A. sojae cell wall extract. Isoflavone content was determined by C18 reverse phase high‐performance chromatography coupled with a photodiode array detector. Antioxidant activities of the extracts were measured using 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) free radical scavenging and β‐carotene cooxidation in a linoleate system. Higher antioxidant activities were observed in wounded and elicitor‐treated extracts when compared with nonwounded control extracts. In addition, the phenolic content was higher in extracts from wounded and elicitor‐treated soybean. Germination for 3 d slightly decreased total isoflavone content (–4.3%); however, wounding increased total isoflavone content (25.8%). The soybean extracts from seeds treated with A. sojae biotic elicitors had the highest total isoflavone contents (9.8 to 11.6 mg/g extract) and displayed the highest antioxidant activities in both the DPPH and β‐carotene assays. Also identified in the wounded and elicitor‐treated extracts were the induced isoflavones glyceollins that contributed to the higher isoflavone contents observed.
Toxicological Evaluation of Polyphenol Extract from Acerola (Malpighia emarginata DC.) Fruit
Authors: Hanamura T. , Aoki H.
Published: March 2008

ABSTRACT:  Acerola (Malpighia emarginata DC.) is known to be one of the best fruits rich in ascorbic acid and polyphenols. Acerola polyphenols (APs) were found to have radical scavenging activities and inhibitory effects on both α‐glucosidase and advanced glycation endproducts (AGEs) production. While polyphenols from several foodstuffs have been shown to be safe, APs, which differ from those of other foodstuffs, have not been evaluated for their toxicological properties. Here, we report preliminary toxicological and safety evaluations of crude APs (C‐AP), which were obtained by eluting an XAD7HP column‐adsorbed fraction of APs with 70% ethanol containing malic acid. The total polyphenol content of C‐AP was 57.7% with the main polyphenols being proanthocyanidin and cyanidin‐3‐α‐O‐rhamnoside. For toxicological evaluations, C‐AP was administered orally to rats at doses of 2000 mg/kg body weight (acute) or 100, 300, and 1000 mg/kg body weight/d for 28 (subacute) and 90 (subchronic) d. In the acute oral toxicological test, no deaths or abnormalities at necropsy on day 14 were observed, confirming that the minimum fatal dose of C‐AP is greater than 2000 mg/kg body weight. In both subacute and subchronic toxicological tests, no death was recorded and the body weights and food intakes of the rats did not differ significantly from the control groups. Besides, there were no abnormal clinical signs related to administration of C‐AP in any of the experimental animals. These results provide an important reference for the safety of APs as a food supplement for human consumption.
Adolescence as a Sensitive Period for Spiritual Development
Authors: Good Marie , Willoughby Teena
Published: March 2008

ABSTRACT—
This paper explores the possibility that adolescence may be a sensitive period for the development of spirituality. Evidence suggests that many of the normative developmental characteristics of adolescence may make teenagers more responsive to spiritual overtures. We review research on the characteristics of adolescent psychological development in conjunction with research on spirituality. On the basis of this research, we hypothesize that adolescents may be more likely than individuals in other age groups to engage in spiritual exploration, have a conversion experience, and make spiritual commitments that endure throughout the life span.
Estimating river flow capacity in practice
Authors: Mc Gahey C. , Samuels P.G. , Knight D.W. , O'Hare M.T.
Published: March 2008

Estimating water level underpins almost all river flood risk management (FRM) tasks from identifying routine channel maintenance actions to developing comprehensive sustainable FRM measures. Research over the past 50 years has seen considerable advances in estimating flow capacity; however, much of this knowledge has not been transferred into industry practice. This paper introduces the Conveyance and Afflux Estimation System (CES/AES) software, the primary output from two UK Environment Agency Research projects, which aim to bridge this gap between science and practice. The focus is the conveyance element, which provides a means for estimating flow capacity for a range of channel types, flow conditions and vegetation and substrate cover. An overview of the methodology and testing is given, together with a practical example of its use in decision making. The method is applied to 16 river sites from the United Kingdom, New Zealand, Argentina and Ecuador, exhibiting model performance for a wide range of channel and flow conditions. Simulations of depth‐averaged velocities at four sites are compared with observations, improving confidence in the underlying methods. The CES/AES toolset is also used in assessing flood risk versus ecological objectives for a small UK river, where vegetation is of significant conservation value but impacts flow capacity.
Functional Mapping of the
Candida albicans
Efg1 Regulator
Authors: Noffz Christine S. , Liedschulte Vanessa , Lengeler Klaus , Ernst Joachim F.
Published: March 2008

Efg1p is a key transcriptional regulator in
Candida albicans
which controls various aspects of morphogenesis and metabolism in this organism. Efg1p contains a central basic helix-loop-helix (bHLH) domain, flanked by sequences highly conserved in fungal APSES proteins, as well as polyglutamine stretches at the N- and C-terminal ends. A systematic deletion approach to specify functional domains of Efg1p revealed that the APSES domain is essential for morphogenesis of the normal yeast and true hyphal cell forms and that bHLH flanking sequences are needed for Efg1p stability. Additional C-terminal sequences were required for hypha formation on some inducing media, and most Efg1p sequences were needed for chlamydospore morphogenesis. Overexpression of
EFG1
led to pseudohypha formation only if a functional APSES domain was present, while a switch from the opaque to the white cell type in addition depended on the presence of certain N- and C-terminal segments. Yeast two-hybrid experiments revealed that binding of Efg1p to its antagonist Czf1p required two regions outside of the APSES domain, which did not coincide with Efg1p sequences needed for its transcriptional repressor activity. Binding of the Flo8 transcription factor to Efg1p did not require the APSES domain but appeared to occur at two or more redundant domains. In contrast, DNA binding of Efg1p to an MluI cell cycle box (MCB) element solely required the APSES domain. Overall, these results suggest that functional domains of Efg1p are spread throughout most of its sequences, including the central APSES domain involved in DNA binding, as well as flanking regions required for various protein interactions and regulatory activities.
Saccharomyces cerevisiae
Phospholipase C Regulates Transcription of Msn2p-Dependent Stress-Responsive Genes
Authors: Demczuk Agnieszka , Guha Nilanjan , Nguyen Peter H. , Desai Parima , Chang Jennifer , Guzinska Katarzyna , Rollins Janet , Ghosh Chandra C. , Goodwin Leslie , Vancura Ales
Published: March 2008

Phosphatidylinositol phosphates are involved in signal transduction, cytoskeletal organization, and membrane trafficking. Inositol polyphosphates, produced from phosphatidylinositol phosphates by the phospholipase C-dependent pathway, regulate chromatin remodeling. We used genome-wide expression analysis to further investigate the roles of Plc1p (phosphoinositide-specific phospholipase C in
Saccharomyces cerevisiae
) and inositol polyphosphates in transcriptional regulation. Plc1p contributes to the regulation of approximately 2% of yeast genes in cells grown in rich medium. Most of these genes are induced by nutrient limitation and other environmental stresses and are derepressed in
plc1
Δ cells. Surprisingly, genes regulated by Plc1p do not correlate with gene sets regulated by Swi/Snf or RSC chromatin remodeling complexes but show correlation with genes controlled by Msn2p. Our results suggest that the increased expression of stress-responsive genes in
plc1
Δ cells is mediated by decreased cyclic AMP synthesis and protein kinase A (PKA)-mediated phosphorylation of Msn2p and increased binding of Msn2p to stress-responsive promoters. Accordingly,
plc1
Δ cells display other phenotypes characteristic of cells with decreased PKA activity. Our results are consistent with a model in which Plc1p acts together with the membrane receptor Gpr1p and associated G
α
protein Gpa2p in a pathway separate from Ras1p/Ras2p and converging on PKA.
Transcriptional Regulation of the
tad
Locus in
Aggregatibacter actinomycetemcomitans
: a Termination Cascade
Authors: Kram Karin E. , Hovel-Miner Galadriel A. , Tomich Mladen , Figurski David H.
Published: March 2008

The
tad
(
t
ight
ad
herence) locus of
Aggregatibacter actinomycetemcomitans
includes genes for the biogenesis of Flp pili, which are necessary for bacterial adhesion to surfaces, biofilm formation, and pathogenesis. Although studies have elucidated the functions of some of the Tad proteins, little is known about the regulation of the
tad
locus in
A. actinomycetemcomitans
. A promoter upstream of the
tad
locus was previously identified and shown to function in
Escherichia coli
. Using a specially constructed reporter plasmid, we show here that this promoter (
tadp
) functions in
A. actinomycetemcomitans
. To study expression of the pilin gene (
flp-1
) relative to that of
tad
secretion complex genes, we used Northern hybridization analysis and a
lacZ
reporter assay. We identified three terminators, two of which (T1 and T2) can explain
flp-1
mRNA abundance, while the third (T3) is at the end of the locus. T1 and T3 have the appearance and behavior of intrinsic terminators, while T2 has a different structure and is inhibited by bicyclomycin, indicating that T2 is probably Rho dependent. To help achieve the appropriate stoichiometry of the Tad proteins, we show that a transcriptional-termination cascade is important to the proper expression of the
tad
genes. These data indicate a previously unreported mechanism of regulation in
A. actinomycetemcomitans
and lead to a more complete understanding of its Flp pilus biogenesis.
CSF, a Species-Specific Extracellular Signaling Peptide for Communication among Strains of
Bacillus subtilis
and
Bacillus mojavensis
Authors: Pottathil Mridula , Jung April , Lazazzera Beth A.
Published: March 2008

ComX and CSF are
Bacillus subtilis
extracellular signaling peptides. Many different strains of
B. subtilis
do not communicate due to strain-specific variation of ComX. We demonstrate that CSF is a species-specific signaling molecule that partially compensates for the lack of ComX-mediated communication between different strains of
B. subtilis
.
Repair and Antirepair DNA Helicases inHelicobacter pylori
Authors: Kang Josephine , Blaser Martin J.
Published: March 2008

Orthologs of RecG and RuvABC are highly conserved among prokaryotes; inEscherichia coli, they participate in independent pathways that branch migrate Holliday junctions during recombinational DNA repair. RecG also has been shown to directly convert stalled replication forks into Holliday junctions. The bacteriumHelicobacter pylori, with remarkably high levels of recombination, possesses RecG and RuvABC homologs, but in contrast toE. coli, H. pyloriRecG limits recombinational repair. We now show that the RuvABC pathway plays the prominent, if not exclusive, repair role. By introducing anE. coliresolvase (RusA) intoH. pylori, the repair and recombination phenotypes of theruvBmutant but not therecGmutant were improved. Our results indicate that RecG and RuvB compete for Holliday junction structures in recombinational repair, but since a classic RecG resolvase is absent fromH. pylori, deployment of the RecG pathway is lethal. We propose that evolutionary loss of theH. pyloriRecG resolvase provides an “antirepair” pathway allowing for selection of varied strains. Such competition between repair and antirepair provides a novel mechanism to maximize fitness at a bacterial population level.
Incretins: pathophysiological and therapeutic implications of glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1
Authors: Ranganath L R
Published: March 2008

Incretins such as glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are intestinal postprandial hormones that stimulate insulin release from the pancreas as long as circulating glucose concentrations are raised. In addition to their effect on insulin secretion and consequent glucose lowering, GIP and GLP-1, especially the latter, have a number of physiological effects such as inhibition of glucagon release, gastric emptying and food intake, as well as a tropic action on pancreatic B-cell mass. There is currently a pandemic of obesity and diabetes, and existing treatments are largely inadequate both in regard to efficacy as well as their ability to tackle important factors in the pathogenesis of type 2 diabetes (T2D). There is increasing evidence that current treatments do not address the issue of progressive B-cell failure in T2D. Since obesity is the engine that is driving the epidemic of diabetes, it is disappointing that most treatments that succeed in lowering plasma glucose are also associated with weight gain. It is now well established that intensively treated T2D has a better outcome than standard treatment. Consequently, achieving better control of diabetes with lower HbA1c is the goal of optimal treatment. Despite the use of usual therapeutic agents in T2D, often in high doses and as combinations, such as metformin, sulphonylurea, α-glycosidase inhibitors, thiazolidinediones and a number of animal and human insulin preparations, optimal control of glycaemia is not achieved. The use of incretins as therapeutic agents offers a new approach to the treatment of T2D.
Raf kinase inhibitor protein: mechanism of loss of expression and association with genomic instability
Authors: Al-Mulla F , Hagan S , Al-Ali W , Jacob S P , Behbehani A I , Bitar M S , Dallol A , Kolch W
Published: March 2008

Aims:

Raf kinase inhibitory protein (RKIP; also known as PEBP, for phosphatidylethanolamine-binding protein) is an endogenous inhibitor of the Raf– MAPK kinase (MEK)–MAP kinase pathway. It has emerged as a significant metastasis suppressor in a variety of human cancers including colorectal cancer (CRC) and was recently shown to regulate the spindle checkpoint in cultured cells. This study aims at correlating RKIP expression with chromosomal instability in colorectal cancer samples and identifies possible mechanisms of RKIP loss.

Methods:

Chromosomal instability was assessed using metaphase-based comparative genomic hybridisation (CGH) and loss of heterozygosity (LOH) in 65 cases with microsatellite stable CRC and correlated with RKIP expression. Methyl-specific PCR was used on DNA extracted from 82 cases with CRC to determine CpG methylation status at the RKIP promoter and the results correlated with RKIP protein expression.

Results:

We demonstrate for the first time that in microsatellite stable (MSS) CRC, the number of chromosomal losses is inversely proportional to RKIP expression levels. We also show that methylation of the RKIP promoter is a major mechanism by which RKIP expression is silenced in CRC.

Conclusions:

RKIP loss by hypermethylation of its promoter could have a significant influence on colorectal cancer aneuploidy, which might explain its association with metastatic progression.
In quest of justice? Clinical prioritisation in healthcare for the aged
Authors: Pedersen R , Nortvedt P , Nordhaug M , Slettebø Å , Grøthe K H , Kirkevold M , Brinchmann B S , Andersen B
Published: March 2008

Background:

A fair distribution of healthcare services for older patients is an important challenge, but qualitative research exploring clinicians’ consideration in daily clinical prioritisation in healthcare services for the aged is scarce.

Objectives:

To explore what kind of criteria, values, and other relevant considerations are important in clinical prioritisations in healthcare services for older patients.

Design:

A semi-structured interview-guide was used to interview 45 clinicians working with older patients. The interviews were analysed qualitatively using hermeneutical content analysis and template organising style.

Participants:

20 physicians and 25 nurses working in public hospitals and nursing homes in different parts of Norway.

Results and interpretations:

Important dilemmas relate to under-provision of community care and comprehensive approaches, and over-utilisation of certain specialised services. Overt ageism is generally not reported, but the healthcare services for the aged seem to be inadequate due to more subtle processes, for example, dominating considerations and ideals and operating conditions that do not pay sufficient attention to older patients’ needs and considerations of justice. Clinical prioritisations are described as being dominated by adapting traditional biomedical approaches to the operating conditions. Many of the clinicians indicate that there is a potential for improving end of life decisions and for reducing exaggerated use of life-prolonging treatment and hospitalisations.

Conclusion:

The interviews in this study indicate that considerations of justice and patients’ perspectives should be given more attention to strike a balance between specialised medical approaches and more general and comprehensive approaches in healthcare services for older patients.
Information disclosure and decision-making: the Middle East versus the Far East and the West
Authors: Mobeireek A F , Al-Kassimi F , Al-Zahrani K , Al-Shimemeri A , al-Damegh S , Al-Amoudi O , Al-Eithan S , Al-Ghamdi B , Gamal-Eldin M
Published: March 2008

Objectives:

to assess physicians’ and patients’ views in Saudi Arabia (KSA) towards involving the patient versus the family in the process of diagnosis disclosure and decision-making, and to compare them with views from the USA and Japan.

Design:

A self-completion questionnaire (used previously to study these issues in Japan and the USA) was translated to Arabic and validated.

Participants:

Physicians (n = 321) from different specialties and ranks and patients (n = 264) in a hospital or attending outpatient clinics from 6 different regions in KSA.

Results:

In the case of a patient with incurable cancer, 67% of doctors and 51% of patients indicated that they would inform the patient in preference to the family of the diagnosis (p = 0.001). Assuming the family already knew, 56% of doctors and 49% of patients would tell the patient even if family objected (p NS). However, in the case of HIV infection, 59% of physicians and 81% of patients would inform the family about HIV status without the patient’s consent (p = 0.001). With regards to withholding ventilatory support, about 50% of doctors and over 60% of patients supported the use of mechanical ventilation in a patient with advanced cancer, regardless of the wishes of the patient or the family. Finally, the majority of doctors and patients (>85%) were against assisted suicide.

Conclusions:

Although there was more recognition for a patient’s autonomy amongst physicians, most patients preferred a family centred model of care. Views towards information disclosure were midway between those of the USA and Japan. Distinctively, however, decisions regarding life prolonging therapy and assisted suicide were not influenced to a great extent by wishes of the patient or family, but more likely by religious beliefs.
Access to medical records for research purposes: varying perceptions across research ethics boards
Authors: Willison D J , Emerson C , Szala-Meneok K V , Gibson E , Schwartz L , Weisbaum K M , Fournier F , Brazil K , Coughlin M D
Published: March 2008

Introduction:

Variation across research ethics boards (REBs) in conditions placed on access to medical records for research purposes raises concerns around negative impacts on research quality and on human subject protection, including privacy.

Aim:

To study variation in REB consent requirements for retrospective chart review and who may have access to the medical record for data abstraction.

Methods:

Thirty 90-min face-to-face interviews were conducted with REB chairs and administrators affiliated with faculties of medicine in Canadian universities, using structured questions around a case study with open-ended responses. Interviews were recorded, transcribed and coded manually.

Results:

Fourteen sites (47%) required individual patient consent for the study to proceed as proposed. Three (10%) indicated that their response would depend on how potentially identifying variables would be managed. Eleven sites (38%) did not require consent. Two (7%) suggested a notification and opt-out process. Most stated that consent would be required if identifiable information was being abstracted from the record. Among those not requiring consent, there was substantial variation in recognising that the abstracted information could potentially indirectly re-identify individuals. Concern over access to medical records by an outside individual was also associated with requirement for consent. Eighteen sites (60%) required full committee review. Sixteen (53%) allowed an external research assistant to abstract information from the health record.

Conclusions:

Large variation was found across sites in the requirement for consent for research involving access to medical records. REBs need training in best practices for protecting privacy and confidentiality in health research. A forum for REB chairs to confidentially share concerns and decisions about specific studies could also reduce variation in decisions.
Influence of physicians’ life stances on attitudes to end-of-life decisions and actual end-of-life decision-making in six countries
Authors: Cohen J , van Delden J , Mortier F , Löfmark R , Norup M , Cartwright C , Faisst K , Canova C , Onwuteaka-Philipsen B , Bilsen J ,   on behalf of the Eureld Consortium
Published: March 2008

Aim:

To examine how physicians’ life stances affect their attitudes to end-of-life decisions and their actual end-of-life decision-making.

Methods:

Practising physicians from various specialties involved in the care of dying patients in Belgium, Denmark, The Netherlands, Sweden, Switzerland and Australia received structured questionnaires on end-of-life care, which included questions about their life stance. Response rates ranged from 53% in Australia to 68% in Denmark. General attitudes, intended behaviour with respect to two hypothetical patients, and actual behaviour were compared between all large life-stance groups in each country.

Results:

Only small differences in life stance were found in all countries in general attitudes and intended and actual behaviour with regard to various end-of-life decisions. However, with regard to the administration of drugs explicitly intended to hasten the patient’s death (PAD), physicians with specific religious affiliations had significantly less accepting attitudes, and less willingness to perform it, than non-religious physicians. They had also actually performed PAD less often. However, in most countries, both Catholics (up to 15.7% in The Netherlands) and Protestants (up to 20.4% in The Netherlands) reported ever having made such a decision.

Discussion:

The results suggest that religious teachings influence to some extent end-of-life decision-making, but are certainly not blankly accepted by physicians, especially when dealing with real patients and circumstances. Physicians seem to embrace religious belief in a non-imperative way, allowing adaptation to particular situations.
Teaching medical ethics: what is the impact of role models? Some experiences from Swedish medical schools
Authors: Lynoe N , Löfmark R , Thulesius H O
Published: March 2008

The goal of the present study was to elucidate what influences medical students’ attitudes and interests in medical ethics. At the end of their first, fifth and last terms, 409 medical students from all six medical schools in Sweden participated in an attitude survey. The questions focused on the students’ experience of good and poor role models, attitudes towards medical ethics in general and perceived effects of the teaching of medical ethics. Despite a low response rate at some schools, this study indicates that increased interest in medical ethics was related to encountering good physician role models, and decreased interest, to encountering poor role models. Physicians involved in the education of medical students seem to teach medical ethics as role models even when ethics is not on the schedule. The low response rate prevents us from drawing definite conclusions, but the results could be used as hypotheses to be further scrutinised.
How can we provide effective training for research ethics committee members? A European assessment
Authors: Davies H , Wells F , Druml C
Published: March 2008

Training for members of research ethics committees (RECs) varies from state to state in Europe. To follow this up, the European Forum for Good Clinical Practice organised a workshop in March 2007 to explore these issues and look for solutions. This article summarises the discussion, providing ways forward to develop REC training.
A pleasure among friends: how narghile (waterpipe) smoking differs from cigarette smoking in Syria
Authors: Hammal F , Mock J , Ward K D , Eissenberg T , Maziak W
Published: March 2008

Background:

Throughout the Eastern Mediterranean region (EMR), tobacco is used primarily in two forms: cigarette smoking and waterpipe (called narghile (nar-GIL-eh) in Syria) smoking.

Objective:

To explore whether narghile smokers are different from cigarette smokers in how their smoking habits are embedded in their everyday lives.

Methods:

One-to-one interviews with 16 adult narghile smokers and 16 adult cigarette smokers about their feelings, experiences and beliefs regarding their initiation, use patterns, and attempts to quit.

Findings:

Narghile smokers found that narghile was a pleasurable social experience embedded in cultural rituals. By contrast, cigarette smokers saw their cigarette smoking as a mundane, oppressive, personal addiction. Narghile smokers generally started in their 20s and found that smoking narghile fostered a sense of togetherness and cultural identity, while cigarette smokers started in their early teens, males having started to becoming a “real man”. Unlike cigarette smokers who felt stigmatised, narghile smokers generally felt that smoking narghile was socially accepted. Cigarette smokers believed that cigarettes were harmful to their health and harmful to those around them, but narghile smokers believed smoking narghile was relatively harmless to themselves or to others. Unlike cigarette smokers who used cigarettes to manage stress, narghile smokers used narghile for entertainment, leisure, and escape. However, frequent narghile smokers confessed that they felt addicted in much the same way as cigarette smokers. Cigarette smokers and narghile smokers viewed quitting as a matter of will and conviction. Most cigarette smokers had tried to quit. Very few narghile smokers had ever tried to quit, and most were not interested in quitting. Disturbingly, some cigarette smokers had tried to quit cigarettes by switching to smoking narghile, but later relapsed to smoking cigarettes.

Conclusions:

This exploratory study suggests that Syrian narghile smokers are different from Syrian cigarette smokers in their perceptions and beliefs about their smoking, and in their smoking patterns and lived experiences with tobacco. Our findings indicate that further in-depth research is need in the EMR to understand both modes of smoking to develop effective mode-specific prevention and cessation approaches. This study also raises concerns about a possible pattern where cigarette smokers are using narghile as a method for quitting cigarettes, and then relapsing.
The Strecker reaction — an examination in terms of no-barrier theory
Authors: Guthrie J Peter , Bhaskar Goonisetty
Published: March 2008

For those examples of the Strecker reaction where information about both rate and equilibrium is available, we have been able to calculate rate constants for the addition of cyanide ion to the iminium ion by the no-barrier theory (NBT) approach. Both experimental and calculated values are for reaction in aqueous solution. Only for the reactions of benzaldehyde with benzyl or allyl amines and HCN are the equilibrium constants and rate constants for the final, rate-determining, step directly available from the literature. For the reactions of acetone with ammonia, methylamine, or dimethylamine and HCN rate constants for the retro-Strecker cleavage and the equilibrium constants for the overall Strecker reaction have been reported. These equilibrium constants, combined with equilibrium constants for iminium ion formation, which can be extracted from information in the literature, allow calculation of the equilibrium constants for the final step of these Strecker reactions. No-barrier theory has already been applied to carbonyl additions, including cyanohydrin formation; this report provides further evidence for the generality of this approach for calculating rate constants without using any kinetic information.Key words: Strecker reaction, rate constant, equilibrium constant, no-barrier theory, computation.
Benzamide hydrolysis in strong acids — The last word
Authors: Cox Robin A
Published: March 2008

Recently it has become apparent that the mechanism of amide hydrolysis in relatively dilute strong acid media is the same as the one observed for ester and benzimidate hydrolysis, two water molecules reacting with the O-protonated amide in the rate-determining step. This is not the whole story, however, at least for benzamide, N-methylbenzamide, and N,N-dimethylbenzamide, since the observed rate constants for these substrates deviate upwards from the observed excess acidity correlation lines at acidities higher than about 60% H2SO4, meaning that another, faster, reaction with a different mechanism is taking over at higher acidities. It has never been clear what this latter mechanism was until the work reported in this paper. An exhaustive excess acidity analysis of all the available measured reaction rate constants for the three substrates in three different acidic media, aqueous H2SO4, aqueous HClO4, and aqueous HCl, shows that this second mechanism involves a second rate-determining proton transfer to the O-protonated benzamide, followed by (or possibly concerted with) irreversible loss of +NH4 to give an acylium ion. Subsequent reaction of this with water (or bisulfate, etc.) eventually gives the observed carboxylic acid product. This latter reaction mechanism has never been previously considered for amide hydrolysis, but it may not be uncommon; at least one other reaction with a similar mechanism is known, and another possible case is suggested.Key words: amides, benzamides, hydrolysis, excess acidity, mechanism, acid media.
Triterpenoids from Saussurea ussuriensis
Authors: Li Xue-Hu , Feng Jia-Tao , Shi Yan-Ping
Published: March 2008

From an extract of the whole plant of Saussurea ussuriensis, three new triterpenoids, 1β-hydroxy-ursa-9(11), 12-dien-3β-yl palmitate (ussuriensin A) (1), 1β-hydroxy-oleana-9(11), 12-dien-3β-yl palmitate (ussuriensin B) (2), and 28-hydroxy-taraxast-20(30)-ene-3β-yl palmitate (ussuriensin C) (3), as well as five known triterpenoids, 11β-hydroxy-urs-12-en-3-one (4), 11β-hydroxy-urs-12-en-3β-yl palmitate (5), ursa-9(11), 12-dien-3-one (marsformosanone) (6), 3β-hydroxy-30-norlupan-20-one (7), and taraxast-20(30)-en-3β, 21α-diol (8) were isolated. Their structures were characterized by various spectroscopic methods, including 1D NMR, 2D NMR, and HR-ESI-MS.Key words: Compositae, Saussurea ussuriensis, triterpenoids, ursane, oleanane, taraxastane.
Determination of manganese and nickel in slurry sampling by graphite furnace atomic absorption spectrometry
Authors: Pereira Luciano Almeida , Borges Simone Soares de O. , Castro Maurício Costa , Neto Waldomiro Borges , Windmöller Cláudia Carvalhinho , da Silva José Bento Borba
Published: March 2008

Methods for the determination of manganese and nickel in lake and marine sediment slurries by graphite furnace atomic absorption spectrometry using permanent modifiers are proposed. The slurries were maintained homogeneous with air bubbling with an aquarium pump. For manganese, the best modifier was ruthenium permanent with mo of 0.9 pg and of 1.0, 1.2, 1.5, and 1.8 pg, for Rh, without modifier, Ir, and Zr, respectively. For nickel, the best modifier was rhodium permanent with mo of 33 pg, followed by 85, 120, 132, and 240 pg, without modifier, Zr, Ir, and Ru, respectively. After determining manganese and nickel in two certified marine sediment samples (n = 10) from NRCC, PACS-2, and MESS-2, and in the San Joaquin 2079 soil, the results agreed at the confidence level of 95% with the certified value for all analytes studied using aqueous calibration. Calibration curves of all analytes had correlation coefficients R2 higher than 0.99. Recovery studies made in four levels for each analyte in sediments from Lake Pampulha showed acceptable values. The limits of detection (LODs) were 4.0 and 0.9 µg L-1 for manganese and nickel, respectively.Key words: manganse, nickel, sediments, GF AAS.
Kinetic plasticity and the determination of product ratios for kinetic schemes leading to multiple products without rate laws — New methods based on directed graphs
Authors: Andraos John
Published: March 2008

This paper presents two new and fast methods of determining product ratios for kinetic schemes leading to more than one product on which the Acree–Curtin–Hammett (ACH) principle is based. The methods involve rewriting a given kinetic scheme as a directed graph with nodes and arrows connecting the nodes and takes advantage of the directionality of the kinetic arrows and the enumeration of paths to the various target product nodes. The first, based on path divergent trees, is computationally simpler but works under a specific set of conditions, whereas the second, based on an adapted version of Chou’s graphical method, works for all cases. By means of illustrated examples, both methods are shown to be completely verifiable with conventional more tedious treatments based on rate law determinations. The directed graph concept also works for kinetic schemes that involve entirely equilibrated species. In addition, the paper extends these ideas to variants of the basic ACH scheme, thereby testing the validity of the ACH principle and bringing about a deeper understanding of it. Generalization of the results yields a new parameter, called degree of kinetic plasticity, which completely describes the dynamics of kinetic resolution between the boundary limits of ACH behaviour (100% kinetic plasticity) and anti-ACH behaviour (100% kinetic rigidity). It is shown that this parameter is a good descriptor of all possible scenarios between and including these limits and can be determined experimentally by conducting a new kind of product study that tracks the behaviour of final product excesses as a function of initial substrate excesses. The resulting plot is always linear with a positive slope. The degree of kinetic plasticity is found by simply subtracting the slope from unity. These ideas are tested on complex kinetic schemes exhibiting dynamic kinetic resolution (DKR) by means of organocatalysis.Key words: physical organic chemistry, kinetics, mechanism, directed graph, Chou digraph, Chou graphical rule, Acree-Curtin-Hammett principle, product ratio, dynamic kinetic resolution, organocatalysis.
Comparison of stand density measures in even-aged regrowth eucalypt forest of southern Tasmania
Authors: West P. W.
Published: March 2008

Most of the existing measures of density of even-aged forests are estimates of the degree of approach of a stand to a "maximum density" condition. The measures differ in the way in which these estimates are made. The definition of maximum density may vary with forest type and the purpose for which the measure of density is to be used. In the present work, 17 different density measures are computed for sets of thinned and unthinned stands of regrowth eucalypt forest in southern Tasmania. The various measures are all presented in mathematically equivalent forms so that the relationships between them can be easily seen. Stands at maximum density are defined as those undergoing substantial and continuing competition-induced mortality. This contrasts with much other work in which "normal" stands are considered to be at maximum density. Reasons for the different approach to maximum density with the present forest type are discussed. The 17 density measures are found to fall into four groups (i) stand basal area itself, (ii) other measures based on sums of tree diameters, (iii) measures based on sums of tree volumes, and (iv) measures based on sums of tree heights. Many of the more complex measures are shown to have little appreciable difference from their simpler counterparts in the way they represent density.
Influence of seed size on germination and early development of loblolly pine (Pinustaeda L.) germinants
Authors: Dunlap J. R. , Barnett J. P.
Published: March 2008

Seed size was examined as a possible explanation for variation in the size of containerized loblolly pine (Pinustaeda L.) seedlings. Under laboratory conditions of minimal environmental stress, larger seed were found to germinate more quickly and produce a larger germinant after 28 days of growth. In a similar experiment conducted under greenhouse growing conditions, large seed produced the largest seedlings. Size differences among seedlings in both experiments resulted from differences in the rate of germination unique to each seed size class. Consequently, seedling size and possibly uniformity of growth were considered to be a function of germination patterns which were strongly influenced by seed size and weight.
Effects of organic–mineral soil mixtures and increasing temperature on the respiration of coniferous raw humus material
Authors: Salonius P. O.
Published: March 2008

A marked stimulation of the decomposition of L, F, and H layers of a podzol organic horizon was found when these materials were mixed with mineral soil from the B horizon. However, decomposition was much more enhanced by increasing the temperature of these materials. The potential benefits of forest plantation site preparation by deeply mixing the surface organic horizon with underlying mineral soil are discussed.
Stand structure, thinning prescriptions, and density indexes in a Douglas-fir thinning study, Western Washington, U.S.A.
Authors: Oliver Chadwick Dearing , Murray Marshall D.
Published: March 2008

A Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) thinning study was established in 1959 in a stand begun after logging in 1930. Thinnings to set basal area densities were done in 1959, 1962, 1966, and 1970. On each plot both large and small trees were removed since average basal area per tree was kept constant before and after thinning. Volume growth varied greatly between plots of the same age, initial basal area, and site because of differences in stand structure. Large trees on a plot grew more per tree and per basal area than small trees. Stand basal area, stand volume, number of stems, or number of dominant and codominant trees were not closely related to volume growth per hectare, although density indexes giving weight to larger trees showed the closest relation. The lack of close relation between stand density indexes and growth found here and elsewhere probably means the indexes do not uniquely define stand structures; it does not necessarily mean that thinning will not increase volume growth per hectare. Volume growth per hectare after thinning to a given basal area density will be greater and probably more consistent if larger trees are left and enough time is allowed for the stand to recover following thinning.
Carbon storage in managed forests
Authors: Cooper Charles F.
Published: March 2008

The mass of carbon stored in forests is an important component of the global carbon cycle. A general model is developed to relate average carbon storage over the lifetime of a forest managed for sustained yield to the maximum biomass of the same forest at maturity. Point of inflection of stand growth is established using the Richards function. If a forest is managed for maximum sustained yield of biomass, mean lifetime carbon storage is about one-third that at maturity. Point of growth inflection has little effect on this fraction. When accumulation and decomposition of detritus after harvest are added, the fraction is about 0.5 in temperate deciduous forests, less in the tropics, and more in boreal forests. Harvest at financial maturity, by shortening the rotation, disproportionately reduces lifetime carbon storage, to perhaps 0.2 of the maximum. Nontimber values may affect carbon storage either positively or negatively. Forest regrowth and multispecies agricultural systems that include trees may account for more carbon storage in the tropics than is sometimes assumed.
Effects of thinning and nitrogen fertilization on growth of Douglas-fir: relative contribution of foliage quantity and efficiency
Authors: Brix H.
Published: March 2008

The aboveground biomass of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) and annual production over 7 years was studied in relation to thinning and nitrogen fertilization. Biomass yield of both treatments increased during the first 3–4 years then decreased for fertilization but not with thinning. Treatments doubled biomass production of individual trees over the study period when applied separately and quadrupled it when combined. Annual biomass production per unit of foliage (E) increased during the first 3–4 years, but was at or below control level after 7 years. The increased E accounted for 20, 37, and 27% of the stemwood dry matter response to thinning, fertilization and the combined treatments, respectively; the remainder was attributed to an increase in foliage biomass. Thinning, but not fertilization, influenced distribution of radial growth along the stem, increasing growth only below the top one-third of the stem. This pattern was related to crown development.
The influence of ozone on Pinusstrobus L. pollen germination
Authors: Benoit L. F. , Skelly J. M. , Moore L. D. , Dochinger L. S.
Published: March 2008

Along the Blue Ridge Parkway in Virginia, branchlets and pollen were collected from native eastern white pine (Pinusstrobus L.) trees that were sensitive, intermediate, and tolerant to oxidant air pollution based on foliar symptom expression. Fumigation of branchlets with 0.10 ppm ozone (O3) for 4 or 8 h/day until anthesis did not affect pollen production or germinability. However, the percent germination was significantly (P ≤ 0.01) reduced in pollen exposed under wet conditions to 0.15 O3 for 4 h. The importance of this finding in the reproduction of pines is discussed.