bluuebunny/crossref_metadata_2025 huggingface dataset:
Protection of crayfish, Cambarus clarkii, from white spot syndrome virus by polyclonal antibodies against a viral envelope fusion protein
Authors: Li H‐X , Meng X‐L , Xu J‐P , Lu W , Wang J
Published: May 2005

White spot syndrome virus (WSSV) is a large double‐stranded DNA virus, causing considerable mortality in penaeid shrimp and other crustaceans. WSSV produces five major structural proteins, including two major envelope proteins, VP28 and VP19. To produce VP28 and VP19 as a single protein for antibody production, DNA sequences encoding both open reading frames were fused together and cloned into pET‐22b(+) expression vector. The fusion protein, VP(19+28), was expressed in Escherichia coli, purified using Ni2+His affinity chromatography and injected into a rabbit. Antiserum collected from the immunized rabbit was tested in vivo for ability to protect crayfish, Cambarus clarkii, from disease caused by WSSV. Fifteen days after challenge with WSSV, treatment with VP(19+28) antiserum gave 100% protection against disease in the ambient temperature range of 15–22 °C and 65% protection at a constant temperature of 26 °C. These results demonstrated VP(19+28) antiserum is effective in protection of crayfish from WSSV and confirmed that VP19 and VP28 play an important role in WSSV host infection. Targeting both VP19 and VP28 may be effective for the design of both immunotherapeutic medicines and reagents to detect WSSV.
Development of a PCR Assay for the Molecular Detection of Phytophthora boehmeriae in Infected Cotton
Authors: Shen G. , Wang Y. C. , Zhang W. L. , Zheng X. B.
Published: May 2005

Cotton blight, caused by the oomycete Phytophthora boehmeriae, is a serious disease of cotton in China. In wet weather conditions, P. boehmeriae is usually the primary pathogen, followed by many saprophytic fungi and pathogens such as Pythium spp., Fusarium spp., Rhizoctonia and others. As P. boehmeriae grows much slower than other pathogens, it is difficult to isolate and identify. A rapid and accurate method for its specific identification is necessary for the detection of blight in infected cotton tissue. The internal transcribed spacer (ITS) regions of ribosomal DNA (rDNA) from three isolates of P. boehmeriae were amplified using the polymerase chain reaction (PCR) with the universal primers DC6 and ITS4. PCR products were cloned and sequenced. The sequences were aligned with those published of 50 other Phytophthora species, and a region specific to P. boehmeriae was used to construct the specific PCR primers PB1 and PB2. Over 106 isolates of 14 Phytophthora species and at least 20 other fungal species were used to check the specificity of the primers. PCR amplification with primers PB1 and PB2 resulted in the amplification of a product of approximately 750 bp only from isolates of P. boehmeriae. Using primers PB1 and PB2, detection sensitivity was approximately 10 fg DNA/μl. In inoculated plant material, P. boehmeriae could be detected in tissue 1 day after inoculation, prior to the appearance of symptoms. The PB primer‐based PCR assay provides an accurate and sensitive method for detecting P. boehmeriae in cotton tissue.
Elevated circulating levels of matrix metalloproteinase‐9 and ‐2 in patients with symptomatic coronary artery disease
Authors: Zeng B. , Prasan A. , Fung K. C. , Solanki V. , Bruce D. , Freedman S. B. , Brieger D.
Published: May 2005

Abstract

Background:  Matrix metalloproteinases (MMP‐9 and MMP‐2) have been implicated in development of atherosclerosis and plaque rupture in acute coronary syndromes (ACS).

Aim:  To determine the relationship between circulating MMPs and symptomatic coronary artery disease.

Methods:  Plasma levels of MMP‐9 and MMP‐2 were measured in patients with ACS, stable angina (SA) and in controls, using a quantitative gelatin zymography. These measurements were correlated with markers of systemic inflammation (hs‐CRP) in all subjects and myocardial injury (troponin T) in patients with ACS.

Results:  Plasma MMP‐9 in ACS was greater than in SA, and was greater in SA than in controls (P < 0.01 ACS vs SA and controls, P < 0.01 SA vs control). Plasma MMP‐2 was significantly greater in ACS than SA or controls (P < 0.01 vs SA and controls). There was strong overall relationship between hs‐CRP and MMP‐9 (r = 0.65, P < 0.0001) driven by a significant relationship in ACS patients (r = 0.58, P = 0.02), as there was no significant association in SA or controls. A weaker overall correlation was found between hs‐CRP and MMP‐2 (r = 0.39, P = 0.02), but no significant relationship was present for either of the two patient subgroups or controls. There was no correlation between levels of troponin T and MMP‐9, MMP‐2 or hs‐CRP in ACS patients.

Conclusion:  Quantitative gelatin zymography identifies increased circulating levels of MMP‐9 and MMP‐2 in patients with symptomatic coronary disease. MMP‐9 and MMP‐2 are higher in ACS than SA patients and might have use as markers of plaque rupture or instability. The strong relationship between MMP‐9 and hs‐CRP in ACS patients suggests MMP‐9 might be an additional marker and/or consequence of the inflammatory component in ACS. (Intern Med J 2005; 35: 331–335)
Occupational bladder cancer in New Zealand: a 1‐year review of cases notified to the New Zealand Cancer Registry
Authors: Dryson E. , Walls C. , McLean D. , Pearce N.
Published: May 2005

Abstract

Aim: To identify which cases of adult bladder cancer notified to the New Zealand Cancer Registry in 2001 had a probable occupational cause.

Methods: Occupational Safety and Health (OSH), in conjunction with the Massey University Centre for Public Health Research, interviewed and obtained an occupational history for 210 (162 men, 48 women) cases.

Results: Of the 162 male cases (response rate 65%), 45 (28%) were considered to be ‘probable’ occupational cancers. Of the 48 female cases (response rate 76%), three cases (6%) were considered to be ‘probable’ occupational cancers. The largest occupational group for men was truck drivers, which made up 51% of probable cases. Other common groups were engineering and metal workers (18%), crop farmers/orchardists (7%), textile and leather workers (7%), painters/furniture finishers (7%), and plastics manufacturing workers (4%). The three female cases considered to be of occupational origin included two textile workers and one telephonist.

Conclusions: The percentage of cases considered to be of occupational origin is similar to that reported in Europe and the United States, indicating that occupational cancer is a major occupational health problem in New Zealand as it is in other parts of the world. (Intern Med J 2005; 35: 343–347)
Comprehensive geriatric assessment for community‐dwelling elderly in Asia compared with those in Japan: I. Singapore
Authors: Matsubayashi Kozo , Ho Han Kwee , Okumiya Kiyohito , Wada Taizo , Ishine Masayuki , Wada Chizu , Xin Zhu Ge , Kita Toru , Kato Yuko , Nishihiro Naoko , Hock Lim Boon
Published: May 2005

Background:  The objective of the present study is to compare the findings of comprehensive geriatric assessments of community‐dwelling elderly people in Singapore with those in Japan..

Methods:  A cross‐sectional, interview‐ and examination‐based study was conducted of community‐dwelling elderly people living in an urban district, Choa Chu Kang, in Singapore and in a rural town, Urausu, in Hokkaido in Japan. Volunteers were recruited by advertising. One hundred and seventeen and 163 community‐dwelling elderly aged 70 years and over in Singapore and Japan, respectively, were examined using a common comprehensive geriatric assessment tool. Interviews pertaining to activities of daily living (ADL), medical and social history, quality of life (QOL) and the 15‐item Geriatric Depression Scale as well as anthropometric, neurobehavioral and blood chemical examinations were included in the assessment. Using unpaired t‐tests and χ2 tests, findings from the two groups were compared.

Results:  Intellectual ADL scores were higher in Japan than in Singapore, while there was no significant difference in basic ADL, instrumental ADL or social ADL between the two groups. The prevalence of depression was lower and QOLs were higher in Singaporean elderly subjects than in Japanese. Scores on cognitive functions were higher in Japanese subjects than in Singaporean ones. Mean blood pressure measurements and the prevalence of both hypertension and impaired glucose tolerance were higher in Singapore than in Japan.

Conclusion:  Comparative findings between comprehensive geriatric assessment of community‐dwelling elderly in Singapore and in Japan were reported. Between these highly economically developed countries, there was no significant difference in such ADLs as basic, information‐related, instrumental and social, but there were differences in the intellectual ADL scores. Japanese elderly people were more highly educated than their Singaporean counterparts, however, higher QOLs and a lower prevalence of depression in the community‐dwelling elderly population were revealed in Singapore than in Japan. Understanding of the need to control chronic risk factors such as hypertension or diabetes mellitus was less popularly spread among community‐dwelling elderly in Singapore than in Japan.
Comprehensive geriatric assessment for community‐dwelling elderly in Asia compared with those in Japan: II. Hongchon in Korea
Authors: Sakagami Teiji , Okumiya Kiyohito , Ishine Masayuki , Wada Taizo , Kita Toru , Kawakita Toshiko , Fushida Mutsuko , Kyu Kim Sang , Sak Park Moo , Yook Choi Soon , Jai‐Kook Cho , Matsubayashi Kozo
Published: May 2005

Background:  The objective of the present study is to compare the findings of comprehensive geriatric assessment between community‐dwelling elderly people in Korea and in Japan.

Methods:  A cross‐sectional, interview‐ and examination‐based study was undertaken of community‐dwelling elderly people living in a rural district, Hongchon, in Korea and in a rural town, Sonobe, in Kyoto in Japan. Two hundred and thirty‐eight community‐dwelling elderly people aged 60 years and over in Korea and 411 aged 65 years and over in Kyoto, Japan were examined using a common comprehensive geriatric assessment tool. Interviews concerning activities of daily living (ADL), medical and social history, quality of life (QOL) and the 15‐item Geriatric Depression Scale were conducted as well as anthropometric and blood chemical examinations. Findings from the two groups were compared using unpaired T‐test and χ2 test.

Results:  All examined ADLs except for the social ADL were significantly lower in Korean elderly subjects than in Japanese. Only the mean social ADL score of each group showed no difference. The prevalence of depression assessed by the 15‐item Geriatric Depression Scale was higher in Korean elderly subjects than in Japanese. Scores for QOL indices were lower in the Korean subjects than in the Japanese. Korean subjects showed higher mean body mass indices, blood sugar concentrations and prevalences of impaired glucose tolerance than Japanese. Mean age, sex ratio and living situation (living alone or not, etc.) were not significantly different between the two groups.

Conclusion:  Comparative features of comprehensive geriatric assessment of community‐dwelling elderly between Korea and Japan were reported. Although both are highly economically developed countries in Asia, it was revealed that elderly Korean subjects were in poorer condition with regard to such ADLs as those relating to basic activities, information, instrumental and intellectual ones, in comparison with Japanese subjects. The one exception was the social ADL. At the same time, Korean subjects showed a higher prevalence of depression and lower scores for QOL. A high prevalence of impaired glucose tolerance in Korea was noteworthy. We assumed psychosocial rather than biological factors had produced such diversities.
Community‐acquired pneumonia in older adults
Authors: Loeb Mark
Published: May 2005

Community‐acquired pneumonia is an important cause of morbidity and mortality in older adults. Residents of long‐term care facilities, a distinct subpopulation of elderly people, are at particularly high risk for developing nursing‐home acquired pneumonia. In this review, the best evidence for etiology, risk factors, clinical presentation, management and prevention of community acquired pneumonia in persons 65 years and older are summarized. The emphasis is on the clinical characteristics unique to community‐acquired pneumonia in the elderly as well as nursing home acquired pneumonia.
Teaching the future teachers in geriatrics: The 10‐year success story of the European Academy for Medicine of Aging
Authors: Bonin‐Guillaume S , Kressig RW , Gavazzi G , Jacques M‐C , Chevalley T , Pautex S , Vischer U , Zekry D , Michel J‐P
Published: May 2005

While celebrating the 10th anniversary of the European Academy for Medicine of Aging (EAMA), former students and EAMA members identify 10 major factors that led to the success of the EAMA: (i) extremely motivated academic geriatricians anticipating the future care needs of the oldest old Europeans; (ii) EAMA's exclusive goal ‘to teach the future teachers in geriatrics’; (iii) an excellent location in Switzerland with outstanding teaching facilities; (iv) a residential course of four 1‐week sessions over 2 years consisting of innovative and contemporary content with the strong involvement of the EAMA's scientific board members; (v) a multicultural melting pot of young, promising geriatricians (from 24 different countries) who constitute the academic geriatric relief of tomorrow; (vi) numerous teachers and experts from all over the world; (vii) permanent and informal interaction between students and teachers; (viii) students’ evaluations show marked progress in regard to scientific content, formulation of take‐home messages and techniques of oral presentation before and after each course (over 90% of the participants of the first four courses were promoted and 20% obtained a full professorship in geriatrics); (ix) the well‐designed EAMA concept is confirmed and validated with the recent accreditation by the European Community and the European Union Geriatric Medicine Society; and former students constituting a strong international network have been able to launch similar courses in elsewhere (Middle East Academy for Medicine of Aging; Latin America Academy for Medicine of Aging; Saint Louis University Geriatric Academy; and the European Nursing Academy for the care of the olders).
Neurons in the lateral sacral cord of the cat project to periaqueductal grey, but not to thalamus
Authors: Klop Esther Marije , Mouton Leonora J. , Kuipers Rutger , Holstege Gert
Published: May 2005

Previous work of our laboratory has shown that neurons in the lateral sacral cord in cat project heavily to the periaqueductal grey (PAG), in all likelihood conveying information from bladder and genital organs. In humans this information usually does not reach consciousness, which raises the question of whether the lateral sacral cell group projects to the thalamus. After wheatgerm agglutinin‐horseradish peroxidase (WGA‐HRP) injections into the sacral cord, anterogradely labelled fibers were found in the thalamus, specifically in the ventral anterior and ventral lateral nuclei, the medial and intralaminar nuclei, the lateral ventrobasal complex/ventroposterior lateral nucleus, and the nucleus centre médian, lateral to the fasciculus retroflexus. Much denser projections were found to the central parts of the PAG, mainly to its dorsolateral and ventrolateral parts at caudal levels and lateral parts at intermediate levels. In a subsequent retrograde tracing study, injections were made in those parts of the thalamus that received sacral fibers, as found in the anterograde study. Labelled neurons were observed in the sacral cord, but not in the lateral sacral cell group. In contrast, a small control injection in the caudal PAG resulted in many labelled neurons in the lateral sacral cord. These results suggest that afferent information regarding micturition and sexual behaviour is relayed to the PAG, rather than to the thalamus.
The photoperiod entrains the molecular clock of the rat pineal
Authors: Engel Lydia , Lorenzkowski Verena , Langer Christina , Rohleder Nils , Spessert Rainer
Published: May 2005

The suprachiasmatic nucleus‐pineal system acts as a neuroendocrine transducer of seasonal changes in the photoperiod by regulating melatonin formation. In the present study, we have investigated the extent to which the photoperiod entrains the nonself‐cycling oscillator in the Sprague–Dawley rat pineal. For this purpose, the 24‐h expression of nine clock genes (bmal1, clock, per1, per2, per3, cry1, cry2, dec1 and dec2) and the aa‐nat gene was monitored under light‐dark 8 : 16 and light‐dark 16 : 8 in the rat pineal by using real‐time RT‐PCR. The 24‐h pattern of the expression of only per1, dec2 and aa‐nat genes was affected by photoperiod. In comparison with the short photoperiod, the duration of elevated expression under the long photoperiod was elongated for per1 and shortened for dec2 and aa‐nat. For each of the genes, photoperiod‐dependent variations partly persisted under constant darkness. Therefore, the pineal clockwork appears to memorize the photoperiod of prior entrained cycles. The findings of the present study indicate that the nonself‐cycling oscillator of the rat pineal is entrained by photoperiodic information and therefore that it participates in seasonal timekeeping.
‘Compulsive’ lever pressing in rats is enhanced following lesions to the orbital cortex, but not to the basolateral nucleus of the amygdala or to the dorsal medial prefrontal cortex
Authors: Joel Daphna , Doljansky Julia , Schiller Daniela
Published: May 2005

In a new rat model of obsessive–compulsive disorder (OCD), ‘compulsive’ behaviour is induced by attenuating a signal indicating that a lever‐press response was effective in producing food. We have recently found that compulsive lever pressing is increased following lesions to the rat orbital cortex, in accordance with several lines of evidence implicating the orbitofrontal cortex in the pathophysiology of OCD. In view of the functional similarities between the orbital cortex, the basolateral nucleus of the amygdala and the medial prefrontal cortex, the present study compared the effects of lesions to these three regions. The present study replicated the finding that lesions to the rat orbital cortex enhance compulsive lever pressing. In contrast, lesions to the dorsal medial prefrontal cortex and to the basolateral amygdala did not affect compulsive lever pressing. A comparison of these findings to current knowledge regarding similarities and differences in the functioning of the three regions sheds light on the mechanism by which signal attenuation induces compulsive lever pressing and on the role played by the orbital cortex in compulsive behaviour.
Electrophysiological evidence for cortical plasticity with movement repetition
Authors: Halder Pascal , Sterr Annette , Brem Silvia , Bucher Kerstin , Kollias Spyros , Brandeis Daniel
Published: May 2005

The role of movement repetition and practice has been extensively studied as an aspect of motor skill learning but has rarely been investigated in its own right. As practice is considered a prerequisite for motor learning we expected that even the repetitive execution of a simple movement would rapidly induce changes in neural activations without changing performance. We used 64‐channel event‐related potential mapping to investigate these effects of movement repetition on corresponding brain activity in humans. Ten healthy right‐handed young adults performed a power grip task under visual force control to ensure constant behaviour during the experimental session. The session consisted of two parts intersected by a break. For analysis each part was subdivided into two runs to control for potential attention or fatigue effects, which would be expected to disappear during the break. Microstate analysis revealed that distinct topographies and source configurations during movement preparation, movement execution and feedback integration are responsive to repetition. The observed patterns of changes differed for the three microstates, suggesting that different, repetition‐sensitive neural mechanisms are involved. Moreover, this study clearly confirms that movement repetition, in the absence of skill learning, is capable of inducing changes in neural networks.
The scrapie prion protein is present in flotillin‐1‐positive vesicles in central‐ but not peripheral‐derived neuronal cell lines
Authors: Pimpinelli Federica , Lehmann Sylvain , Maridonneau‐Parini Isabelle
Published: May 2005

Transmissible prion diseases are fatal neurodegenerative diseases associated with the conversion of the normal host prion protein (PrPc) into an abnormal isoform (PrPSc) that accumulates in brain. This pathology affects neurons of the central nervous system whereas no clear toxic effect has been reported for peripheral neurons. We examined the subcellular distribution of PrPc and PrPSc in the scrapie‐infected mouse neuronal cell lines GT1‐7 and N2a, derived, respectively, from the central and peripheral nervous system. We observed that in both cell types, PrPc is present in the endocytic compartment, mainly in LAMP‐1‐positive late endosomes, but excluded from LYAAT‐1‐lysosomes. In contrast, PrPSc was distributed differently in the two cell lines. In infected N2a, PrPSc and PrPc had comparable distribution patterns. In infected GT1‐7, PrPSc is present in an additional vesicular compartment which is flotillin‐1‐positive. The level of expression of flotillin‐1 is higher in GT1‐7 than in N2a cells, but no difference is observed between infected and noninfected cells. In Alzheimer's disease patients, it has been reported that flotillin‐1 is abundant in brain areas containing the β‐amyloid protein, which accumulates in endosomal vesicles in primary neurons. We propose that the flotillin compartment could store aggregated proteins and play a role in these neurodegenerative pathologies.
The ability of axons to regenerate their growth cones depends on axonal type and age, and is regulated by calcium, cAMP and ERK
Authors: Chierzi Sabrina , Ratto Gian Michele , Verma Poonam , Fawcett James W.
Published: May 2005

The processes activated at the time of axotomy and leading to the formation of a new growth cone are the first step in regeneration, but are still poorly characterized. We investigated this event in an in vitro model of axotomy performed on dorsal root ganglia and retinal explants. We observed that the dorsal root ganglion axons and retinal ganglion cell axons, which had grown out on a poly d‐lysine/laminin substrate at the time of culture preparation greatly differed in their regenerative response after a subsequent in vitro lesion made far from the cell body. The majority of axons of adult dorsal root ganglia but only a small percentage of axons of adult retinal ganglion cells regenerated new growth cones within four hours after in vitro axotomy, though both kinds of axons were growing before the lesion. The depletion of extracellular calcium and the inhibition of extracellular‐signal regulated kinase 1,2 (ERK) and protein kinase A (PKA) at the time of injury significantly impaired the capacity of dorsal root ganglia axons to re‐initiate growth cones without affecting growth cone motility. Pharmacological treatments directed at increasing the level of cAMP promoted growth cone regeneration in adult retinal ganglion cell axons in spite of the low regenerative potential exhibited in normal conditions. Understanding the cellular mechanisms activated at the time of lesion and leading to the formation of a new growth cone is necessary for devising treatments aimed at enhancing the regenerative response of injured axons.
Presence of vesicular glutamate transporter‐2 in hypophysiotropic somatostatin but not growth hormone‐releasing hormone neurons of the male rat
Authors: Hrabovszky Erik , Turi Gergely F. , Liposits Zsolt
Published: May 2005

Recent evidence indicates that hypophysiotropic gonadotropin‐releasing hormone (GnRH), corticotropin‐releasing hormone (CRH) and thyrotropin‐releasing hormone (TRH) neurons of the adult male rat express mRNA and immunoreactivity for type‐2 vesicular glutamate transporter (VGLUT2), a marker for glutamatergic neuronal phenotype. In the present study, we investigated the issue of whether these glutamatergic features are shared by growth hormone‐releasing hormone (GHRH) neurons of the hypothalamic arcuate nucleus (ARH) and somatostatin (SS) neurons of the anterior periventricular nucleus (PVa), the two parvicellular neurosecretory systems that regulate anterior pituitary somatotrophs. Dual‐labelin situhybridization studies revealed relatively few cells that expressed VGLUT2 mRNA in the ARH; the GHRH neurons were devoid of VGLUT2 hybridization signal. In contrast, VGLUT2 mRNA was expressed abundantly in the PVa; virtually all (97.5 ± 0.4%) SS neurons showed labelling for VGLUT2 mRNA. In accordance with these hybridization results, dual‐label immunofluorescent studies followed by confocal laser microscopic analysis of the median eminence established the absence of VGLUT2 immunoreactivity in GHRH terminals and its presence in many neurosecretory SS terminals. The GHRH terminals, in turn, were immunoreactive for the vesicular γ‐aminobutyric acid (GABA) transporter, used in these studies as a marker for GABA‐ergic neuronal phenotype. Together, these results suggest the paradoxic cosecretion of the excitatory amino acid neurotransmitter glutamate with the inhibitory peptide SS and the cosecretion of the inhibitory amino acid neurotransmitter GABA with the stimulatory peptide GHRH. The mechanisms of action of intrinsic amino acids in hypophysiotropic neurosecretory systems require clarification.
Will the (German) NAIRU Please Stand Up?
Authors: Franz Wolfgang
Published: May 2005

This paper deals with a critical assessment of the ‘non-accelerating inflation rate of unemployment’ (NAIRU) for Germany. There are quite a few obstacles to perceiving the NAIRU as an easy-to-use analytical instrument: the possibility of a non-vertical Phillips curve, the occurrence of shocks and hysteresis effects, and the (mis-)measurement of important variables, cointegration issues and a time variability of the NAIRU. A new attempt is made to estimate a NAIRU for Germany using direct measures of inflationary expectations. However, by any method, the NAIRU is very hard to determine and subject to considerable arbitrariness.
Continuing Vocational Training Forms and Establishment Productivity in Germany
Authors: Zwick Thomas
Published: May 2005

This paper provides evidence of the productivity effects of different continuing vocational training forms in Germany. Using the waves 1997-2001 of the IAB establishment panel, it is found that formal external courses have the largest positive impact on productivity. Formal internal courses and quality circles have a smaller positive impact. Self-induced learning, participation at seminars and talks and job rotation do not enhance productivity while training on the job has a negative productivity impact. Establishments with an inefficient production structure decide to offer training in order to boost productivity. This paper also shows that taking into account selectivity of the training decision, unobserved time-invariant heterogeneity, human resource practices, as well as establishment and employee characteristics has an important impact on the measurement results.
Cortisol Reactivity Is Positively Related to Executive Function in Preschool Children Attending Head Start
Authors: Blair Clancy , Granger Douglas , Peters Razza Rachel
Published: May 2005

This study examined relations among cortisol reactivity and measures of cognitive function and social behavior in 4‐ to 5‐year‐old children (N=169) attending Head Start. Saliva samples for the assay of cortisol were collected at the beginning, middle, and end of an approximately 45‐min testing session. Moderate increase in cortisol followed by down‐regulation of this increase was positively associated with measures of executive function, self‐regulation, and letter knowledge but not with measures of receptive vocabulary, emotion knowledge, or false belief understanding. Regression analysis indicates that executive function accounted for the association between cortisol reactivity and self‐regulation and letter knowledge.
Group Norms, Threat, and Children's Racial Prejudice
Authors: Nesdale Drew , Maass Anne , Durkin Kevin , Griffiths Judith
Published: May 2005

To assess predictions from social identity development theory (SIDT; Nesdale, 2004) concerning children's ethnic/racial prejudice, 197 Anglo‐Australian children ages 7 or 9 years participated in a minimal group study as a member of a team that had a norm of inclusion or exclusion. The team was threatened or not threatened by an out‐group that was of the same or different race. Consistent with SIDT, prejudice was greater when the in‐group had a norm of exclusion and there was threat from the out‐group. Norms and threat also interacted with participant age to influence ethnic attitudes, although prejudice was greatest when the in‐group had an exclusion norm and there was out‐group threat. The implications of the findings for SIDT are discussed.
Cultural Patterns in Attending to Two Events at Once
Authors: Correa‐Chávez Maricela , Rogoff Barbara , Mejía Arauz Rebeca
Published: May 2005

This study examined cultural differences in children's simultaneous attention to 2 events versus quick alternation in which attending to 1 event momentarily interrupted attending to another. Thirty‐one 6‐ to 10‐year‐old U.S. children of Mexican and European American heritage folded paper figures with 2 other first‐ to third‐grade children and an adult. Mexican heritage children whose mothers averaged 7 grades of school more commonly attended to events simultaneously. European heritage and Mexican heritage children whose mothers had more than 12 grades of school more commonly alternated attention. Differences are interpreted in light of traditional indigenous North and Central American emphasis on learning through observation of ongoing events as well as school practices that emphasize learning by attending to one event at a time.
Small Group Teaching: Perceptions and Problems
Authors: Bogaard Amy , Carey Sabine C. , Dodd Gwilym , Repath Ian D. , Whitaker Richard
Published: May 2005

Seminars and tutorials are a standard part of delivering teaching in politics departments. However, the range of methods used in such small groups is wide and varied as are the perceptions of the purpose of small group teaching (SGT). On the basis of interviews with students and lecturers, we highlight important differences between what lecturers hope to achieve and what students expect to learn in these sessions. We aim to provide a better understanding of the cause of common problems in SGT and to explore how teaching staff might address these shortcomings to maximise the success of small group teaching.
White House Structure and Decision Making: Elaborating the Standard Model
Authors: WALCOTT CHARLES E. , HULT KAREN M.
Published: May 2005

A consensus has emerged about how White House staffs should be organized, which we refer to as the “standard model.” Yet recent presidencies have produced various kinds of dissatisfaction with the performance of the White House staff. Here, we explore whether the new normative understanding of White House structuring for decision making offers prescriptions that are as “good” as they might be. Focusing on the limitations of hierarchical structuring and of multiple advocacy, we urge both a more nuanced view of the nature of White House decision making and a more variegated approach to modeling and prescribing appropriate structures.
The First Debate over the Debates: How Kennedy and Nixon Negotiated the 1960 Presidential Debates
Authors: SELF JOHN W.
Published: May 2005

The 1960 presidential campaign was historic for a number of reasons, most notably for the first‐ever set of general election televised presidential debates between the two major‐party candidates. Much like any political campaign event, the 1960 debates were carefully planned and negotiated before the candidates showed up that September night in a Chicago television studio. This article culled together information from many sources to reveal how the 1960 debates were negotiated between the Nixon and Kennedy campaigns as well as the broadcast network sponsors. This article is part of a larger project to develop a theory of presidential debate negotiation.
Oxidative stress and vascular remodelling
Authors: Fortuño Ana , José Gorka San , Moreno María U. , Díez Javier , Zalba Guillermo
Published: May 2005

Oxidative stress plays an important role in the pathophysiology of vascular diseases. Reactive oxygen species, especially superoxide anion and hydrogen peroxide, are important signalling molecules in cardiovascular cells. Enhanced superoxide production increases nitric oxide inactivation and leads to an accumulation of peroxynitrites and hydrogen peroxide. Reactive oxygen species participate in growth, apoptosis and migration of vascular smooth muscle cells, in the modulation of endothelial function, including endothelium‐dependent relaxation and expression of proinflammatory phenotype, and in the modification of the extracellular matrix. All these events play important roles in vascular diseases such as hypertension, suggesting that the sources of reactive oxygen species and the signalling pathways that they modify may represent important therapeutic targets. Potential sources of vascular superoxide production include NADPH‐dependent oxidases, xanthine oxidases, lipoxygenases, mitochondrial oxidases and nitric oxide synthases. Studies performed during the last decade have shown that NADPH oxidase is the most important source of superoxide anion in phagocytic and vascular cells. Evidence from experimental animal and human studies suggests a significant role of NADPH oxidase activation in the vascular remodelling and endothelial dysfunction found in cardiovascular diseases.
Vitamin D receptor FokI genotype influences bone mineral density response to strength training, but not aerobic training
Authors: Rabon‐Stith Karma M. , Hagberg James M. , Phares Dana A. , Kostek Matthew C. , Delmonico Matthew J. , Roth Stephen M. , Ferrell Robert E. , Conway Joan M. , Ryan Alice S. , Hurley Ben F.
Published: May 2005

To determine the influence of the vitamin D receptor (VDR) gene FokI and BsmI genotype on bone mineral density response to two exercise training modalities, 206 healthy men and women (50–81 years old) were studied before and after ∼5–6 months of either aerobic exercise training (AT) or strength training (ST). A totla of 123 subjects completed AT (51 men, 72 women) and 83 subjects completed ST (40 men, 43 women). DNA was extracted from blood samples of all subjects and genotyping was performed at the VDR FokI and BsmI locus to determine its association to training response. Total body, greater trochanter and femoral neck bone mineral density (BMD) were measured before and after both training programmes using dual‐energy X‐ray absorptiometry. VDR BsmI genotype was not significantly related to BMD at baseline or after ST or AT. However, VDR FokI genotype was significantly related to ST‐ but not AT‐induced changes in femoral neck BMD (P < 0.05). The heterozygotes (Ff) in the ST group approached a significantly greater increase in femoral neck BMD (P= 0.058) compared to f homozygotes. There were no significant genotype relationships in the AT group. These data indicate that VDR FokI genotype may influence femoral neck BMD response to ST, but not AT.
Down regulation of Kv3.4 channels by chronic hypoxia increases acute oxygen sensitivity in rabbit carotid body
Authors: Kääb Stefan , Miguel‐Velado Eduardo , López‐López José Ramón , Pérez‐García M. Teresa
Published: May 2005

The carotid body (CB) chemoreceptors participate in the ventilatory responses to acute and chronic hypoxia (CH). Arterial hypoxaemia increases breathing within seconds, and CB chemoreceptors are the principal contributors to this reflex hyperventilatory response. Acute hypoxia induces depolarization of CB chemoreceptors by inhibiting certain K+ channels, but the role of these channels in CH, as in high‐altitude acclimatization, is less known. Here we explored the effects of prolonged (24–48 h) hypoxic exposure of rabbit CB chemoreceptor cells in primary cultures on the voltage‐dependent K+ currents and on their response to acute hypoxia. We found that CH induces a decrease in the amplitude of outward K+ currents due to a reduction in a fast‐inactivating BDS‐ and highly TEA‐sensitive component of the current. In spite of this effect, acute hypoxic inhibition of K+ currents is increased in CH cultures, as well as hypoxia‐induced depolarization. These data suggest that downregulation of this component (that does not contribute to the oxygen‐sensitive K+ current (IKO2)) participates in the hypoxic sensitization. Pharmacological, immunocytochemical and quantitative PCR (qPCR) experiments demonstrate that CH‐induced decrease in outward K+ currents is due to a downregulation of the expression of Kv3.4 channels. Taken together, our results suggest that CH sensitization in rabbit CB could be achieved by an increase in the relative contribution of IKO2 to the outward K+ current as a consequence of the decreased expression of the oxygen‐insensitive component of the current. We conclude that acute and chronic hypoxia can exert their effects acting on different molecular targets.
Differential responses to CO2 and sympathetic stimulation in the cerebral and femoral circulations in humans
Authors: Ainslie Philip N. , Ashmead Jon C. , Ide Kojiro , Morgan Barbara J. , Poulin Marc J.
Published: May 2005

The relative importance of CO2 and sympathetic stimulation in the regulation of cerebral and peripheral vasculatures has not been previously studied in humans. We investigated the effect of sympathetic activation, produced by isometric handgrip (HG) exercise, on cerebral and femoral vasculatures during periods of isocapnia and hypercapnia. In 14 healthy males (28.1 ± 3.7 (mean ±s.d.) years), we measured flow velocity (; transcranial Doppler ultrasound) in the middle cerebral artery during euoxic isocapnia (ISO, +1 mmHg above rest) and two levels of euoxic hypercapnia (HC5, end‐tidal PCO2, P, =+5 mmHg above ISO; HC10, P=+10 above ISO). Each PET,CO2 level was maintained for 10 min using the dynamic end‐tidal forcing technique, during which increases in sympathetic activity were elicited by a 2‐min HG at 30% of maximal voluntary contraction. Femoral blood flow (FBF; Doppler ultrasound), muscle sympathetic nerve activity (MSNA; microneurography) and mean arterial pressure (MAP; Portapres) were also measured. Hypercapnia increased and FBF by 5.0 and 0.6% mmHg−1, respectively, and MSNA by 20–220%. Isometric HG increased MSNA by 50% and MAP by 20%, with no differences between ISO, HC5 and HC10. During the ISO HG there was an increase in cerebral vascular resistance (CVR; 20 ± 11%), while remained unchanged. During HC5 and HC10 HG, increased (13% and 14%, respectively), but CVR was unchanged. In contrast, HG‐induced sympathetic stimulation increased femoral vascular resistance (FVR) during ISO, HC5 and HC10 (17–41%), while there was a general decrease in FBF below ISO. The HG‐induced increases in MSNA were associated with increases in FVR in all conditions (r= 0.76–0.87), whereas increases in MSNA were associated with increases in CVR only during ISO (r= 0.91). In summary, in the absence of hypercapnia, HG exercise caused cerebral vasoconstriction, myogenically and/or neurally, which was reflected by increases in CVR and a maintained . In contrast, HG increased FVR during conditions of ISO, HC5 and HC10. Therefore, the cerebral circulation is more responsive to alterations in PCO2, and less responsive to sympathetic stimulation than the femoral circulation.
Extension and magnitude of denervation in skeletal muscle from ageing mice
Authors: Wang Zhong‐Min , Zheng Zhenlin , Messi María Laura , Delbono Osvaldo
Published: May 2005

In this work we hypothesized that denervation in flexor digitorum brevis (FDB) muscle from ageing mice is more extensive than predicted by standard functional and structural assays used in the past. In addition, we asked whether denervation is a fully or partially developed process. Despite the reported alteration in skeletal muscle innervation, the quantification of the extension and magnitude of denervation in ageing rodents has remained elusive. To address these two questions we utilized a combination of electrophysiological and immunohistochemical assays directed to detecting the expression of tetrodotoxin (TTX)‐resistant sodium channels (Nav1.5) in FDB muscles from young‐adult and senescent mice. Sodium current density measured with the macropatch cell‐attached technique did not show significant differences between FDB fibres from young and old mice. The TTX dose–response curve, using the whole cell voltage‐clamp technique, showed three populations of fibres in senescent mice, one similar to fibres from young mice (TTX sensitive), another one similar to fibres from experimentally denervated muscle (TTX resistant), and a third group intermediate between these two. Partially and fully denervated fibres added up to approximately 50% of the total number of fibres tested, a number that concurs with the percentage of fibres positive for the Nav1.5 channel by specific immunostaining.
Action potential fidelity during normal and epileptiform activity in paired soma–axon recordings from rat hippocampus
Authors: Meeks Julian P. , Jiang Xiaoping , Mennerick Steven
Published: May 2005

Although action potential initiation and propagation are fundamental to nervous system function, there are few direct electrophysiological observations of propagating action potentials in small unmyelinated fibres, such as the axons within mammalian hippocampus. To circumvent limitations of previous studies that relied on extracellular stimulation, we performed dual recordings: whole‐cell recordings from hippocampal CA3 pyramidal cell somas and extracellular recordings from their axons, up to 800 μm away. During brief spike trains under normal conditions, axonal spikes were more resistant to amplitude reduction than somatic spikes. Axonal amplitude depression was greatest at the axon initial segment < 150 μm from the soma, and initiation occurred ∼75 μm from the soma. Although prior studies, which failed to verify spike initiation, suggested substantial axonal depression during seizure‐associated extracellular K+ ([K+]o) rises, we found that 8 mm[K+]o caused relatively small decreases in axonal spike amplitude during brief spike trains. However, during sustained, epileptiform spiking induced in 8 mm[K+]o, axonal waveforms decreased significantly in peak amplitude. During epileptiform spiking, bursts of two or more action potentials > 20 Hz failed to propagate in most cases. In normal [K+]o at 25 and 32°C, spiking superimposed on sustained somatic depolarization, but not spiking alone, produced similar axonal changes as the epileptiform activity. These results highlight the likely importance of steady‐state inactivation of axonal channels in maintaining action potential fidelity. Such changes in axonal propagation properties could encode information and/or serve as an endogenous brake on seizure propagation.
Bruno Pontecorvo: From slow neutrons to oscillating neutrinos
Authors: Bonolis Luisa
Published: May 2005

Bruno Pontecorvo’s work in neutrino physics is examined and due emphasis is given to the audacity of his ideas both theoretically and experimentally. The account ends with the first solar neutrinos detected by Raymond Davis in 1967 using the radiochemical method developed by Pontecorvo in 1945.
Toward the effective use of voting machines in physics lectures
Authors: Reay Neville W. , Bao Lei , Li Pengfei , Warnakulasooriya Rasil , Baugh Gordon
Published: May 2005

A “voting machine” is a generic name for wireless-keypad in-class polling systems used by students to answer multiple-choice questions during lectures. We present our experiences gained while distributing and using voting machine modules. Using voting machines with carefully designed sets of multiple-choice questions and instantaneous voting summaries improved classroom dynamics and provided students with several opportunities per concept to test their understanding. Three question sets developed for the electricity and magnetism quarter of a year-long introductory physics course are included as examples.
Student understanding of static equilibrium: Predicting and accounting for balancing
Authors: Ortiz Luanna G. , Heron Paula R. L. , Shaffer Peter S.
Published: May 2005

We report on an investigation of student ability to account for static equilibrium in the simple familiar case in which an object is balanced on a frictionless pivot or fulcrum. Written questions were administered to more than 1000 university students who had completed the relevant instruction in introductory calculus-based physics. Almost all the students were able to answer questions about simple systems composed of point-like objects. However, when the mass distribution was continuous, most students attributed equilibrium to forces of equal magnitude applied on both sides of the fulcrum. Moreover, many students treated horizontal and tilted bodies, even if they were at rest, as distinct cases. The difficulties we identified were very persistent. Hands-on activities that were not influenced by research results had no discernible effect on student performance. Direct attempts to address specific difficulties using lecture demonstrations based on the research tasks described in this article led to some improvement. Greater success has been achieved by using a tutorial in which students work in small groups on experiments and exercises suggested by research findings.
Helical waves on a vortex filament
Authors: Dmitriyev Valery P.
Published: May 2005

A vortex filament in a perfect fluid is an excellent system, similar to an elastic string, elastic membrane, diffusion tube, and conducting rod, for presenting the equations of mathematical physics. A small amplitude helical wave spreading along an unstretchable vortex filament is shown to obey the linear Schrödinger equation. Taking into account elastic properties of the filament leads to the Klein-Gordon equation.