bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Nitrogen Deposition: Results of a Temporal‐Spatial Analysis of Deciduous Forests in South Sweden
Authors: Diekmann M. , Brunet J. , Rühling Å. , Falkengren‐Grerup U.
Published: February 2008

Abstract: We studied permanent plots in deciduous forests in two provinces of South Sweden, Skåne (127 plots) and Småland (116 plots). Vegetation data were sampled in 1983 and 1993 and used to calculate weighted averages of Ellenberg indicator values for light, reaction (pH) and nitrogen. Soil samples were collected from all plots in 1993 for determination of pH, organic matter content and potential net nitrogen mineralization (minN). Data on minN were also available for 66 plots in Skåne from 1983. Nitrogen deposition is considerably higher in Skåne than in Småland. The same holds true for total minN, minNH4+, minNO3‐‐, and the proportion of total minN due to nitrate (nitrification ratio). According to the comparison of average Ellenberg indicator values between 1983 and 1993, the stands had become darker (not in the heavily managed plots), more acid and nitrogen rich, except at the most acid sites where only minor changes could be observed. The nitrification ratio was significantly higher in 1993 than in 1983. Mean soil nitrification ratios were determined for the most common species in both regions. The means were higher in Skåne than in Småland. It is likely that nitrogen deposition causes an increase in nitrification rate and nitrification ratio. This ratio is a significant determinant of the species composition in deciduous forests.
Biomass Production and Carbohydrate Content of Arabidopsis thaliana at Atmospheric CO2 Concentrations from 390 to 1680 μl l‐1
Authors: Van der Kooij L. A. W. , Kok L. J. De , Stulen I.
Published: February 2008

Abstract: The concentration dependency of the impact of elevated atmospheric CO2 concentrations on Arabidopsis thaliana L. was studied. Plants were exposed to nearly ambient (390), 560, 810, 1240 and 1680 μl I‐1 CO2 during the vegetative growth phase for 8 days. Shoot biomass production and dry matter content were increased upon exposure to elevated CO2. Maximal increase in shoot fresh and dry weight was obtained at 560 μl I‐1 CU2, which was due to a transient stimulation of the relative growth rate for up to 3 days. The shoot starch content increased with increasing CO2 concentrations up to two‐fold at 1680 μl I‐1 CO2, whereas the contents of soluble sugars and phenolic compounds were hardly affected by elevated CO2. The chlorophyll and carotenoid contents were not substantially affected at elevated CO2 and the chlorophyll a/b ratio remained unaltered. There was no acclimation of photosynthesis at elevated CO2; the photosynthetic capacity of leaves, which had completely developed at elevated CO2 was similar to that of leaves developed in ambient air. The possible consequences of an elevated atmospheric CO2 concentration to Arabidopsis thaliana in its natural habitat is discussed.
Systematic Exploration of the Equine Tarsus by Ultrasonography
Authors: Vilar J. M. , Rivero M. A. , Arencibia A. , Morales I. , Pinedo M.
Published: February 2008

The authors propose a standard protocol of ultrasonographic exploration of the tarsal region in transversal and longitudinal planes, with the aim to spread with an accurate location of the anatomical structures. For this study, 10 adult horses of different races and ages (ranged 5–10 years) were used, with the characteristic of not having suffered any kind of tarsic pathology. The equipment was a real time ultrasound machine with a 7.5 mHz lineal transducer. Some different anatomical structures in this region of the hind‐limb such as the tendons, ligaments, muscles and articular components were identified and labelled as regards their echoic characteristics.
Artificial covering on trap nests improves the colonization of trap‐nesting wasps
Authors: Taki Hisatomo , Kevan Peter G. , Viana Blandina F. , Silva Fabiana O. , Buck Matthias
Published: February 2008

To evaluate the role that a trap‐nest cover might have on sampling methodologies, the abundance of each species of trap‐nesting Hymenoptera and the parasitism rate in a Canadian forest were compared between artificially covered and uncovered traps. Of trap tubes exposed at eight forest sites in six trap‐nest boxes, 531 trap tubes were occupied and 1216 individuals of 12 wasp species of four predatory families, Vespidae (Eumeninae), Crabronidae, Sphecidae and Pompilidae emerged over 2 years, and no bee species were found. Results indicated that artificial covering led to a significant increase in the number of nested tubes ofAncistrocerus adiabatus,Ancistrocerus antilope,Ancistrocerus campestrisandAuplopus mellipes, and significant effects of covering were not found for the other species. No significant difference in the overall parasitism rate between covered and uncovered traps was noted. These suggested that the covering technique could provide more opportunities for some wasp species to colonize trap nests.
Abundance and distribution of organic mound‐building ants of theFormica rufagroup in Yellowstone National Park
Authors: Risch A. C. , Jurgensen M. F. , Storer A. J. , Hyslop M. D. , Schütz M.
Published: February 2008

Red wood ants (Formica rufagroup) are ubiquitous in many conifer and mixed‐conifer forests of northern Europe and Asia. In contrast, relatively little is known about the abundance and distribution of the 24 North AmericanF. rufagroup species. As ants are important components of most soil invertebrate communities and are considered ecosystem engineers that alter the flow of energy and nutrients through terrestrial systems, it is important to gain information on their distribution and abundance. We conducted a survey for red wood ant mounds in Yellowstone National Park (YNP), Wyoming/Montana, USA, where human disturbance has been kept to a minimum for over 130 years. We found a total of 85 red wood ant mounds (0.11 to 0.17 mounds/ha) on 327 km of roads and 180 km of the hiking trails we surveyed. The occurrence of ant mounds was higher then expected by random distribution at elevations between 1600 and 2400 m, annual precipitation of 250 to 760 mm, middle and late successional lodgepole pine, late successional Douglas fir forest and non‐forested grassland/sagebrush prairie vegetation. Additionally, mounds were clustered in gently sloped not north‐exposed locations and in areas that had not recently burned. Most of the mounds detected were inhabited byFormica obscuripesForel, which occupied 94% of the mounds sampled. Based on a multi‐criteria binary Geographic Information System model that we developed, we found that ant mounds were to be expected with a high probability in less then 1% of the YNP area. These results together with the detected low density and small size of the red wood ant mounds within the study area suggest that these insects have a much lower impact on invertebrate biodiversity and ecosystem processes, such as forest productivity and carbon and nutrient cycling on the ecosystem scale compared with their counterparts in European or Asian systems.
Genetic divergence of Trichogramma aurosum Sugonjaev and Sorokina (Hymenoptera: Trichogrammatidae) individuals based on ITS2 and AFLP analysis
Authors: Samara R. , Monje J. C. , Reineke A. , Zebitz C. P. W.
Published: February 2008

Taxonomy and phylogeny of members of the genus Trichogramma is often critical because of the fact that proper species discrimination can only be achieved by male morphology. Cryptic species, particularly when only females are available (in case of parthenogenetic species or strains), are common in this genus with consequences for practical purposes like biocontrol, unless males can be obtained after antibiotic treatment. The internally transcribed spacer 2 region of the ribosomal DNA was used to assess the identity of Trichogramma aurosum Sugonjaev and Sorokina individuals collected on eggs of Nematus tibialis Newman (Hymenoptera: Tenthredinidae) from different locations in Middle Europe. Amplified products were identical in length (ca. 450bp), sequences showed a high percent similarity (>96%), and no cryptic species could be detected in the samples. In contrast, a comparison with T. aurosum populations from the USA showed values between 86% and 90%. Additional studies are needed to clarify the relationship between US and European populations. Furthermore, amplified fragment length polymorphism (AFLP) analysis was conducted with T. aurosum wasps collected at 25 different European locations. One hundred and twenty‐three AFLP fragments could be detected using three different AFLP primer combinations of which 98% were polymorphic in more than one individual. An analysis of genetic distances based on the obtained AFLP markers indicated the existence of some genetic variability between the European T. aurosum individuals and allowed a grouping according to their geographic origin. This study represents the first successful application of the AFLP marker technique to such tiny insects as Trichogramma species.
Stratification and symptom characteristics of non‐erosive reflux disease based on acid and duodenogastroesophageal reflux
Authors: Xiong Li‐Shou , Chen Min‐Hu , Lin Jin‐Kun , Hu Pin‐Jin
Published: February 2008

Background and Aim:  The subgroups and symptom characteristics of non‐erosive reflux disease (NERD) based on acid and duodenogastroesophageal reflux may be different in Chinese patients to Western patients. This study aimed to explore the stratification and symptom characteristics of patients with NERD.

Methods:  Patients with typical heartburn and/or acid regurgitation symptoms were enrolled. Each patient filled out a questionnaire. An upper gastrointestingal endoscopy was performed for each patient followed by simultaneous ambulatory 24‐h esophageal pH and Bilitec (bilirubin) monitoring. A symptom index (SI) of ≥50% was considered to be positive.

Results:  Eighty‐two consecutive NERD patients were evaluated. Abnormal (NERD pH+) and normal (NERD pH–) 24‐h pH tests were found in 24 (29.3%) and 58 (70.7%) patients, respectively. Among 42 NERD pH– patients who reported heartburn symptoms during monitoring, SI was positive in 19 (45.2%) patients (NE‐SI+) and negative in 23 (54.8%) patients (NE‐SI–). Pathological duodenogastroesophageal reflux (DGER) was found in 43 (52.4%) patients. No significant differences were noted regarding the prevalence of other upper gastrointestinal symptoms, except for acid regurgitation in NERD pH+ and NERD pH– groups. Additionally, no significant differences were seen in the prevalence of other symptoms, except for chest pain, in groups with pathological and normal DGER.

Conclusion:  The proportion of NERD patients with pathological acid reflux was somewhat lower than that reported in Western countries. The role of DGER in NERD may be important. It is difficult to differentiate whether NERD patients have pathological acid or bile reflux according to symptoms.
Highly schizotypal students have a weaker sense of self‐agency
Authors: Asai Tomohisa , Tanno Yoshihiko
Published: February 2008

Schizotypy can be seen as an indicator of a predisposition to schizophrenia. It is possible that schizotypal people have an abnormal self‐consciousness, especially with regard to the sense of self‐agency. Students were rated using the Schizotypy Traits Questionnaire (STA). They were asked to press a button, which generated a tone after some delay. They were then required to judge whether they felt they or someone else had generated the tone. The results showed that the high schizotypy group had a weaker sense of self‐agency than the low schizotypy group. The present study used an experimental method to show that schizotypal traits are correlated with an abnormal sense of self‐agency.
Psychiatric symptoms in adolescents with Internet addiction: Comparison with substance use
Authors: Yen Ju‐Yu , Ko Chih‐Hung , Yen Cheng‐Fang , Chen Sue‐Huei , Chung Wei‐Lun , Chen Cheng‐Chung
Published: February 2008

Aims:  The aim of the present study was to compare psychiatric symptoms between adolescents with and without Internet addiction, as well as between analogs with and without substance use.

Methods:  A total of 3662 students (2328 male and 1334 female) were recruited for the study. Self‐report scales were utilized to assess psychiatric symptoms, Internet addiction, and substance use.

Results:  It was found that Internet addiction or substance use in adolescents was associated with more severe psychiatric symptoms. Hostility and depression were associated with Internet addiction and substance use after controlling for other symptoms.

Conclusions:  This result partially supports the hypothesis that Internet addiction should be included in the organization of problem behavior theory, and it is suggested that prevention and intervention can best be carried out when grouped with other problem behaviors. Moreover, more attention should be devoted to hostile and depressed adolescents in the design of preventive strategies and the related therapeutic interventions for Internet addiction.
Establishing the cut‐off point for the Oppositional Defiant Behavior Inventory
Authors: Harada Yuzuru , Saitoh Kazuhiko , Iida Junzo , Sasayama Daimei , Sakai Ayako , Imai Junko , Iwasaka Hidemi , Hirabayashi Michiko , Yamada Satoru , Hirabayashi Shinichi , Uchiyama Tokio , Amano Naoji
Published: February 2008

Abstract  The purpose of the present paper was to make a detailed examination of the cut‐off point for the Oppositional Defiant Behavior Inventory (ODBI). The subjects were 56 untreated boys (age 6–15 years), who were diagnosed to have oppositional defiant disorder and who presented between December 2001 and March 2008. Controls were 690 boys with no history of contacting hospitals and no developmental or behavioral disorders at two elementary schools and two junior high schools in a city and its suburbs. It was shown that the level of opposition in boys could be evaluated regardless of the age groups by the ODBI, because there was no significant difference in the ODBI score for the one‐way analysis of variance. Based on the sensitivity (88.2%), specificity (90.0%), positive predictive value (75.0%) and negative predictive value (95.7%), a score of 20 points was thus established as a suitable cut‐off point to distinguish the children who are eligible for ODD diagnosis from those who are not.
Assessment of risk of venous thromboembolism and its possible prevention in psychiatric patients
Authors: Malý Radovan , Masopust Jiří , Hosák Ladislav , Konupčíková Kateřina
Published: February 2008

Aims:  The aim of the present study was to compile a specific algorithm of prevention of venous thromboembolism in hospitalized psychiatric patients because this specific issue has not been addressed sufficiently in the literature.

Methods:  The computer database MEDLINE was searched using key words (schizophrenia OR depression OR bipolar) AND (antipsychotic OR antidepressant) AND (venous thromboembolism OR pulmonary embolism) AND (prevention OR prophylaxis) in 2006.

Results:  Based on the literature regarding non‐surgical and surgical patients with respect to specificities in mental disorders (obesity induced with psychotropic drugs, possible catatonia, physical restraint, potential dehydration, antipsychotic treatment), a scoring system and a synoptic algorithm of prevention of venous thromboembolism modified for hospitalized psychiatric patients, were suggested.

Conclusions:  According to the authors' knowledge this is the first attempt to establish such guidelines exclusively in psychiatry. Individual preventative clinical measures are suggested, ranging from regular physical exercise of lower extremities to repeated parenteral application of high doses of heparin tailored to every patient's risk for venous thromboembolism. Economic data support implementation of a proposed decision procedure into psychiatric clinical practice. Prospective discussion of its international applicability would be beneficial from both the clinical and the scientific points of view.
Psychometric properties of the Korean version of the Short Post‐Traumatic Stress Disorder Rating Interview (K‐SPRINT)
Authors: Kim Tae‐Suk , Chung Moon Yong , Kim Won , Koo Young Jin , Ryu Seong Gon , Kim Eui‐Jung , Woo Jong‐Min , Kim Tae‐Hyung , Yang Jong‐Chul , Choi Kyeong‐Sook , Pae Chi‐Un , Seo Ho‐Joon , Lim Hyun‐Kook , Chae Jeong‐Ho ,   Disaster Psychiatry Committee in Korean Academy of Anxiety Disorders
Published: February 2008

Aims:  The Short Post‐traumatic Stress Disorder (PTSD) Rating Interview (SPRINT) is a validated, eight‐item, brief global assessment scale for PTSD. This report investigated the psychometric properties of the Korean version of the SPRINT (K‐SPRINT).

Methods:  Eighty‐seven PTSD patients, 47 other psychiatric patients, and 63 healthy control subjects were enrolled in the study. All subjects completed a psychometric assessment package that included the K‐SPRINT and the Korean versions of the Clinician‐Administered PTSD Scale (CAPS), the Beck Depression Inventory (BDI), and the State Trait Anxiety Inventory (STAI).

Results:  The K‐SPRINT showed good internal consistency (Cronbach's α = 0.86) and test–retest reliability (r = 0.82). K‐SPRINT showed moderatecorrelations with CAPS (r = 0.71). An exploratory factor analysis produced one K‐SPRINT factor. The optimal diagnostic efficiency (91.9%) of the K‐SPRINT was found at a total score of 15, at which point the sensitivity and specificity were 90.8% and 92.7%, respectively.

Conclusions:  The present findings demonstrate that the K‐SPRINT had good psychometric properties and can be used as a reliable and valid instrument for the assessment of PTSD.
Addition of antipsychotics to medication regimens during schizophrenic inpatient care
Authors: Koyama Asuka , Ito Hiroto , Nakanishi Miharu , Sawamura Kanae , Higuchi Teruhiko
Published: February 2008

Aims:  The objective of the present study was to identify schizophrenia inpatients who had their original regimen augmented with additional antipsychotics during acute inpatient care, and to clarify the factors associated with these additions.

Methods:  The subjects were 204 schizophrenia inpatients at 34 acute care hospitals, of whom 42 (20.6%) had further antipsychotics added to their medication regimen during hospitalization.

Results:  Compared with patients who were not prescribed additional antipsychotics, the subjects were typically discharged with higher dosages of antipsychotics, principally low‐potency medications. Patients who exhibited aggressive behavior, who had no physical illness, or whose psychiatrists preferred typical antipsychotics, were more likely to be prescribed additional new antipsychotics.

Conclusions:  Alternative approaches such as intensive care for aggressive patients and educational intervention with psychiatrists may prove useful in stabilizing patients without adding new antipsychotics unless absolutely necessary, and in simplifying medication regimens.
Effectiveness of mirtazapine for nausea and insomnia in cancer patients with depression
Authors: Kim Sung‐Wan , Shin Il‐Seon , Kim Jae‐Min , Kim Young‐Chul , Kim Kyu‐Sik , Kim Ki‐Min , Yang Su‐Jin , Yoon Jin‐Sang
Published: February 2008

Aims:  The purpose of the present paper was to evaluate the effectiveness of mirtazapine orally disintegrating tablets for nausea and sleep disturbance, which are common and distressing symptoms of cancer.

Methods:  This was a 4‐week, prospective, open‐labeled study of cancer patients. Assessments were performed at baseline and on days 1, 3, 5, 7, 14, and 28. Primary outcome measures were the Clinical Global Impression scale for nausea/vomiting and the Chonnam National University Hospital–Leeds Sleep Evaluation Questionnaire (C‐LSEQ) including total amount of night sleep time. The secondary outcome measures consisted of pain items in the 36‐item Short Form Health Survey, the Montgomery–Asberg Depression Rating Scale (MADRS), and the EuroQoL (EQ)‐5D. Forty‐two cancer patients were enrolled.

Results:  Those with nausea (n = 28) improved significantly from day 1. The total night sleep time and each item on the C‐LSEQ improved from days 1–5. The scores on the MADRS and the depression/anxiety dimension and visual analog scale of EQ‐5D improved significantly from the first week. Pain measures also improved from day 1. Exacerbation of sleepiness developed in approximately one‐third of subjects during the initial few days, but disappeared gradually.

Conclusion:  In the present study mirtazapine rapidly improved nausea, sleep disturbance, pain and quality of life, as well as depression in cancer patients. Mirtazapine may be an effective treatment option in managing cancer patients with multiple distressing symptoms, including nausea and sleep disturbance.
Correlation between addictive behaviors and mental health in university students
Authors: Okasaka Yoshiko , Morita Nobuaki , Nakatani Yoji. , Fujisawa Kunihiko
Published: February 2008

Aims:  The present study aims to clarify the relationships of addictive behaviors and addiction overlap to stress, acceptance from others and purpose in life.

Methods:  A survey was conducted on 691 students at eight universities. The Eating Attitude Test‐20 was used to identify students with food addiction or food addictive tendencies. The Kurihama Alcoholism Screening Test was used to identify students with alcohol addiction or alcohol addictive tendencies. The Fagerström Test for Nicotine Dependence was used to identify students with nicotine addictive tendencies or nicotine addiction. The Visual Analog Scale was used to assess stress and acceptance from others. The Purpose in Life Test was used to measure meaning and purpose in life. Results were compared between students with addictive behaviors, with addictive tendencies and without addictive behaviors.

Results:  Significant differences among the three groups were observed for stress, acceptance from others, and Purpose in Life scores for students with food and nicotine addiction, but no significant differences existed in relation to alcohol addiction. In addition, 28.8% of students displayed addictive behaviors in one of the three areas (food, alcohol or nicotine), 8.5% displayed addictive behaviors in two of the three areas, and 0.4% had addictive behaviors in all three areas. Significant differences existed in stress and acceptance from others among students with one addictive behavior, ≥two addictive behaviors and no addictive behaviors. However, no significant differences existed in Purpose in Life scores with respect to overlapping addictions.

Conclusion:  The results suggest a relationship between mental health, addictive behaviors and overlapping addiction among university students.
Self‐injury in Japanese junior and senior high‐school students: Prevalence and association with substance use
Authors: Matsumoto Toshihiko , Imamura Fumi
Published: February 2008

The present study examined the prevalence of self‐injury and its association with substance abuse in 2974 junior and senior high‐school students, by self‐reporting questionnaires. Consequently, 9.9% of students (boys, 7.5%; girls, 12.1%) reported an experience of self‐injury at least once. Significant differences were found in substance use‐related problems including alcohol abuse, smoking, and illicit drug use (P < 0.001) between students with and without an experience of self‐injury. The results also suggest that self‐injuring students may more easily gain access to illicit drugs even if they had not yet experienced the use of illicit drugs. Self‐injury in adolescence may be associated with substance use and is considered to be a risk factor predicting future illicit drug use.
Effect of a functional single nucleotide polymorphism in the 2′,3′‐cyclic nucleotide 3′‐phosphodiesterase gene on the expression of oligodendrocyte‐related genes in schizophrenia
Authors: Iwamoto Kazuya , Ueda Junko , Bundo Miki , Nakano Yoko , Kato Tadafumi
Published: February 2008

Aims:  Although the expression of oligodendrocyte‐related genes in post‐mortem brains of patients with schizophrenia is consistently reported to be downregulated, the cause of the change remains unclear. The A‐allele of rs2070106 within the 2′,3′‐cyclic nucleotide 3′‐phosphodiesterase (CNP), an oligodendrocyte‐related gene, was reported to show reduced expression compared with the G‐allele, and proposed to be associated with schizophrenia.

Methods:  The effect of the rs2070106 genotype on the expression of CNP and other oligodendrocyte‐related genes was examined using data previously obtained from DNA microarray studies of post‐mortem brains.

Results:  It was found that the effect of rs2070106 genotype on the CNP expression was transcript specific, and that the genotype was not associated with the expression of other oligodendrocyte‐related genes.

Conclusions:  The rs207016 genotype is not likely to contribute to the reported coordinated down‐regulation of oligodendrococyte‐related genes in schizophrenia.
Encoding problem‐solving strategies in prefrontal cortex: activity during strategic errors
Authors: Genovesio Aldo , Tsujimoto Satoshi , Wise Steven P.
Published: February 2008

The primate prefrontal cortex (PF) plays a central role in choosing goals and strategies. To better understand its mechanisms, we recorded from PF neurons as monkeys used abstract response strategies to select a spatial goal. A visual cue, selected randomly from a set of three cues, appeared on each trial. All three cues were novel when neuronal recording commenced. From trial to trial, the cue could have either been repeated or changed from the previous trial; these were called repeat trials and change trials, respectively. On repeat trials, the monkeys used a Repeat–stay strategy to gain a reward by choosing the same spatial goal as on the previous trial; on change trials, they used a Change–shift strategy to reject the previous goal in favour of an alternative. We reported previously that when monkeys performed the task correctly, many PF neurons had activity encoding one of these two strategies. The monkeys sometimes chose the incorrect strategy, however. Strategy coding was weak or absent during the cue period of error trials which was, for correct trials, the time when the monkeys used a strategy to choose a future goal. By contrast, later in the trial, after the chosen goal had been attained and the monkeys awaited feedback, strategy coding was present and it reflected the strategy used, whether correct or incorrect. The weak cue‐period strategy signal could, whatever its cause, have contributed to the errors made, whereas the activity prior to feedback suggests a role in monitoring task performance.
A TTX‐sensitive local circuit is involved in the expression of PK2 and BDNF circadian rhythms in the mouse suprachiasmatic nucleus
Authors: Baba Kenkichi , Ono Daisuke , Honma Sato , Honma Ken‐ichi
Published: February 2008

The roles of a local circuit of electrophysiological activity were examined in the expression of circadian rhythms in the suprachiasmatic nucleus (SCN) of the adult mouse. The neuronal activity of cultured SCN was suppressed with tetrodotoxin (TTX), an Na+ channel blocker, and the circadian rhythms in mRNA level were assessed for 13 genes by in situ hybridization. SCN slices were cultured for 3 days and TTX was applied at the peak phase of Per1 expression rhythm. The SCN slices were examined at 4‐h intervals up to 32 h after TTX application. The circadian rhythms in the expression of clock genes, Per1, Per2, Bmal1 and Cry1, and of clock‐associated genes, Dec1, Dec2, Rev‐erbα, Rev‐erbβ and DBP, were not affected by TTX treatment. By contrast, TTX completely abolished the circadian rhythm in the BDNF mRNA level and substantially damped the rhythm in PK2. The circadian rhythm in the AVP mRNA level was not changed significantly by TTX. These findings indicate that input through Na+‐channel‐dependent electrophysiological activity is not necessary for the expression of the circadian rhythms of clock and clock‐associated genes, but necessary for full expression of the circadian rhythms of BDNF and PK2 in the SCN. A TTX‐sensitive circuit is involved in the expression of BDNF and PK2 circadian rhythms in the mouse SCN.
Detection of unexpected events during spatial navigation in humans: bottom‐up attentional system and neural mechanisms
Authors: Iaria Giuseppe , Fox Christopher J. , Chen Jen‐Kai , Petrides Michael , Barton Jason J. S.
Published: February 2008

Navigation is a complex cognitive ability requiring the processing and integration of several different types of information extracted from the environment. While navigating, however, an unexpected event may suddenly occur, which individuals are required to detect promptly in order to apply an appropriate behavioural response. The alerting mechanism that is integral to the detection of unexpected events is referred to as the bottom‐up attentional system. Using event‐related functional magnetic resonance imaging, we investigated the neural basis of bottom‐up detection of unexpected events while individuals moved within a virtual environment. We identified activation within a right fronto‐temporo‐parietal network in response to unexpected events while navigating in this virtual environment. Furthermore, when an unexpected event requires an adjusted behavioural response, a region of the right ventrolateral pre‐frontal cortex (areas 45 and 47/12) is selectively activated. Our data replicate earlier findings on the neural mechanisms underlying visual attention and extend these findings to the more complex real‐life ability of spatial navigation, thereby suggesting that these neural mechanisms subserve the bottom‐up attentional systems that are crucial for effective locomotion in real surroundings.
Dextromethorphan is protective against sensitized N‐methyl‐d‐aspartate receptor‐mediated excitotoxic brain damage in the developing mouse brain
Authors: Keller Matthias , Griesmaier Elke , Auer Maria , Schlager Gerald , Urbanek Martina , Simbruner Georg , Gressens Pierre , Sárközy Gergely
Published: February 2008

Enhanced glutamate release and inflammation play an important role in the pathogenesis of developmental brain injury. Although N‐methyl‐d‐aspartate receptor (NMDAR) antagonists potently attenuate neonatal brain damage in several animal models, they can also impact trophic functions in the developing brain. As a consequence, high‐affinity NMDAR antagonists have been shown to trigger widespread apoptotic neurodegeneration in the newborn brain. Dextromethorphan (DM), a low‐affinity NMDAR antagonist with anti‐inflammatory properties, may be neuroprotective against excitotoxic and inflammation‐enhanced excitotoxic brain injury, without the associated stimulation of apoptotic degeneration. Using an established newborn mouse model of excitotoxic brain damage, we determined whether systemic injection of DM significantly attenuates excitotoxic lesion size. We investigated several doses and time regimens; a dose of 5 µg/g DM given in a combination of both pre‐injury and repetitive post‐injury treatment proved most effective. DM treatment significantly reduced lesion size in gray and white matter by reducing cell death as shown by a decreased Fluoro‐Jade B staining and caspase‐3 activation. Pre‐treatment with interleukin‐1β and lipopolysaccharide enhanced NMDAR‐mediated excitotoxic brain injury and microglial cell activation. This sensitizing effect was abolished by DM treatment, as the effectiveness of DM in reducing lesion size and microglial cell activation was similar to phosphate‐buffered saline‐pre‐treated controls. In all cases, no gender‐specific differences were detected. DM treatment did not trigger any apoptotic neurodegeneration (caspase‐3 cleavage, terminal deoxynucleotidyl transferase‐mediated dUTP nick‐end labeling, Fluoro‐Jade B staining). Although functional parameters were not measured, our data corroborate reports that DM is neuroprotective and that it may therefore improve functional outcome following perinatal brain injury.
Left mid‐ventrolateral prefrontal cortex: underlying principles of function
Authors: Kostopoulos Penelope , Petrides Michael
Published: February 2008

There is a growing body of evidence indicating that the mid‐ventrolateral prefrontal cortex in the left hemisphere is involved in some aspect of controlled verbal memory retrieval. Its precise role, however, remains unclear. We tested the hypothesis that when stimuli in memory are related to each other in multiple ways, and therefore familiarity, strong constant stimulus–stimulus links or contextual cues are not sufficient for successful retrieval, control processing emanating from the mid‐ventrolateral prefrontal cortex is required to disambiguate and select the appropriate information among memory traces. We refer to this type of retrieval as active retrieval to distinguish it from automatic retrieval which depends on the simple reactivation of memory traces. Normal human subjects were scanned with functional magnetic resonance imaging while they performed three memory tasks that varied in their demands on active retrieval of verbal information. As the demands on active retrieval increased, there was an increase in the activity within the mid‐ventrolateral prefrontal cortex, bilaterally, but with more prominent activity in the left hemisphere. These activity increases correlated with activity in the posterior temporal region which, in the left hemisphere, is involved in language processing. No significant activity increases were observed in any other prefrontal region. Furthermore, for the retrieval of well‐learned verbally cued conditional motor associations, there were no activity increases in the mid‐ventrolateral prefrontal cortex. The present findings provide strong support for the hypothesis that the mid‐ventrolateral prefrontal cortex, particularly in the left hemisphere, plays a major role in the active retrieval of information from verbal memory.
Effects of FAK ablation on cerebellar foliation, Bergmann glia positioning and climbing fiber territory on Purkinje cells
Authors: Watanabe Fumihiro , Miyazaki Taisuke , Takeuchi Tomonori , Fukaya Masahiro , Nomura Takanori , Noguchi Shigeru , Mori Hisashi , Sakimura Kenji , Watanabe Masahiko , Mishina Masayoshi
Published: February 2008

Focal adhesion kinase (FAK) is a non‐receptor tyrosine kinase that is widely expressed in the brain, and plays key roles in various cellular processes in response to both extracellular and intracellular stimuli. Here, we explored the role of FAK in cerebellar development. In the mouse cerebellum, FAK was found to be distributed as tiny cytoplasmic aggregates in various neuronal and glial elements, including Purkinje cells (PCs), Bergmann glia (BG), parallel fiber (PF)‐terminals and climbing fiber (CF)‐terminals. The neuron/glia‐specific ablation of FAK impaired cerebellar foliation, such as variable decreases in foliation sizes and the lack of intercrural and precentral fissures. Some of the BG cells became situated ectopically in the molecular layer. Furthermore, the FAK ablation altered the innervation territories of CFs and PFs on PCs. CF innervation regressed to the basal portion of proximal dendrites and somata, whereas ectopic spines protruded from proximal dendrites and PFs expanded their territory by innervating the ectopic spines. Furthermore, the persistence of surplus CFs innervating PC somata caused multiple innervation. When FAK was selectively ablated in PCs, diminished dendritic innervation and persistent somatic innervation by CFs were observed, whereas cerebellar foliation and cell positioning of BG were normally retained. These results suggest that FAK in various neuronal and glial elements is required for the formation of normal histoarchitecture and cytoarchitecture in the cerebellum, and for the construction of proper innervation territory and synaptic wiring in PCs.
Long‐term reorganization of respiratory pathways after partial cervical spinal cord injury
Authors: Vinit Stéphane , Darlot Fannie , Stamegna Jean‐Claude , Sanchez Patrick , Gauthier Patrick , Kastner Anne
Published: February 2008

High cervical spinal cord injury (SCI) interrupts bulbospinal respiratory pathways innervating phrenic motoneurons, and induces an inactivation of phrenic nerves (PN) and diaphragm. We have previously shown that the ipsilateral (ipsi) PN was inactivated following a lateral C2 SCI, but was spontaneously partially reactivated 7 days post‐SCI. This phrenic reactivation depended on contralateral (contra) descending pathways, located laterally, that cross the spinal midline. We analysed here whether long‐term post‐lesional changes may occur in the respiratory network. We showed that ipsi PN reactivation was greater at 3 months compared with 7 days post‐SCI, and that it was enhanced after acute contra phrenicotomy (Phx), which also induced a substantial reactivation of the ipsi diaphragm (not detected at 7 days post‐SCI). At 3 months post‐SCI (compared with 7 days post‐SCI), ipsi PN activity was only moderately affected by ipsi Phx or by gallamine treatment, a nicotinic neuromuscular blocking agent, indicating that it was less dependent on ipsi sensory phrenic afferents. After an additional acute contra SCI (C1) performed laterally, ipsi PN activity was abolished in rats 7 days post‐SCI, but persisted in rats 3 months post‐SCI. This activity thus depended on new functional descending pathways located medially rather than laterally. These may not involve newly recruited neurons as retrograde labelling showed that ipsi phrenic motoneurons were innervated by a similar number of medullary respiratory neurons after a short and long post‐lesional time. These results show that after a long post‐lesional time, phrenic reactivation is reinforced by an anatomo‐functional reorganization of spinal respiratory pathways.
Dynamics of action potential backpropagation in basal dendrites of prefrontal cortical pyramidal neurons
Authors: Zhou Wen‐Liang , Yan Ping , Wuskell Joseph P. , Loew Leslie M. , Antic Srdjan D.
Published: February 2008

Basal dendrites of neocortical pyramidal neurons are relatively short and directly attached to the cell body. This allows electrical signals arising in basal dendrites to strongly influence the neuronal output. Likewise, somatic action potentials (APs) should readily propagate back into the basilar dendritic tree to influence synaptic plasticity. Two recent studies, however, determined that sodium APs are severely attenuated in basal dendrites of cortical pyramidal cells, so that they completely fail in distal dendritic segments. Here we used the latest improvements in the voltage‐sensitive dye imaging technique (Zhou et al., 2007) to study AP backpropagation in basal dendrites of layer 5 pyramidal neurons of the rat prefrontal cortex. With a signal‐to‐noise ratio of > 15 and minimal temporal averaging (only four sweeps) we were able to sample AP waveforms from the very last segments of individual dendritic branches (dendritic tips). We found that in short‐ (< 150 µm) and medium (150–200 µm in length)‐range basal dendrites APs backpropagated with modest changes in AP half‐width or AP rise‐time. The lack of substantial changes in AP shape and dynamics of rise is inconsistent with the AP‐failure model. The lack of substantial amplitude boosting of the third AP in the high‐frequency burst also suggests that in short‐ and medium‐range basal dendrites backpropagating APs were not severely attenuated. Our results show that the AP‐failure concept does not apply in all basal dendrites of the rat prefrontal cortex. The majority of synaptic contacts in the basilar dendritic tree actually received significant AP‐associated electrical and calcium transients.
Isolation and identification of amoeba‐resisting bacteria from water in human environment by using an Acanthamoeba polyphaga co‐culture procedure
Authors: Pagnier Isabelle , Raoult Didier , La Scola Bernard
Published: February 2008

Amoeba‐resisting bacteria (ARB) such as Legionella spp. are currently regarded as potential human pathogens living in the environment. To detect ARB from both human and environmental samples, co‐culture with amoebae has been demonstrated as an efficient tool. However, using this procedure, mostly water from cooling towers and hospital water supplies have been investigated as the possible reservoir of ARB. In the present study, we studied ARB population in 77 environmental water samples including rivers, fountains, lakes and domestic wells in the south of France. As a result, a total of 244 isolates corresponding to 89 different species of ARB, but not Legionella spp., were identified. Ability to grow within and/or to be lytic for amoebae was revealed for the first time for several human pathogens. Six isolates are likely to be the members of a new or uncharacterized genus/species. An anaerobic bacterium, Clostridium frigidicarnis was demonstrated to be lytic for amoebae. This preliminary work demonstrates that the water environment in the vicinity of humans is a reservoir of ARB, including well‐known pathogens for which amoebae and/or water was not recognized earlier as a possible reservoir.
Characterization of a homogeneous taxonomic group of marine magnetotactic cocci within a low tide zone in the China Sea
Authors: Pan Hongmiao , Zhu Kailing , Song Tao , Yu‐Zhang Kui , Lefèvre Christopher , Xing Sue , Liu Min , Zhao Sanjun , Xiao Tian , Wu Long‐Fei
Published: February 2008

Magnetotactic bacteria are a heterologous group of motile prokaryotes, ubiquitous in aquatic habitats and cosmopolitan in distribution. Here, we studied the diversity of magnetotactic bacteria in a seawater pond within an intertidal zone at Huiquan Bay in the China Sea. The pond is composed of a permanently submerged part and a low tide subregion. The magnetotactic bacteria collected from the permanently submerged part display diversity in morphology and taxonomy. In contrast, we found a virtually homogenous population of ovoid‐coccoid magnetotactic bacteria in the low tide subregion of the pond. They were bilophotrichously flagellated and exhibited polar magnetotactic behaviour. Almost all cells contained two chains of magnetosomes composed of magnetite crystals. Intriguingly, the combination of restriction fragment length polymorphism analysis (RFLP) and sequencing of cloned 16S rDNA genes from the low tide subregion samples as well as fluorescence in situ hybridization (FISH) revealed the presence of a homogenous population. Moreover, phylogenetic analysis indicated that the Qingdao Huiquan low tide magnetotactic bacteria belong to a new genus affiliated with the α‐subclass of Proteobacteria. This finding suggests the adaptation of the magnetotactic bacterial population to the marine tide.
Gene transcript analysis of assimilatory iron limitation in Geobacteraceae during groundwater bioremediation
Authors: O'Neil Regina A. , Holmes Dawn E. , Coppi Maddalena V. , Adams Lorrie A. , Larrahondo M. Juliana , Ward Joy E. , Nevin Kelly P. , Woodard Trevor L. , Vrionis Helen A. , N'Guessan A. Lucie , Lovley Derek R.
Published: February 2008

Limitations on the availability of Fe(III) as an electron acceptor are thought to play an important role in restricting the growth and activity of Geobacter species during bioremediation of contaminated subsurface environments, but the possibility that these organisms might also be limited in the subsurface by the availability of iron for assimilatory purposes was not previously considered because copious quantities of Fe(II) are produced as the result of Fe(III) reduction. Analysis of multiple Geobacteraceae genomes revealed the presence of a three‐gene cluster consisting of homologues of two iron‐dependent regulators, fur and dtxR (ideR), separated by a homologue of feoB, which encodes an Fe(II) uptake protein. This cluster appears to be conserved among members of the Geobacteraceae and was detected in several environments. Expression of the fur‐feoB‐ideR cluster decreased as Fe(II) concentrations increased in chemostat cultures. The number of Geobacteraceae feoB transcripts in groundwater samples from a site undergoing in situ uranium bioremediation was relatively high until the concentration of dissolved Fe(II) increased near the end of the field experiment. These results suggest that, because much of the Fe(II) is sequestered in solid phases, Geobacter species, which have a high requirement for iron for iron‐sulfur proteins, may be limited by the amount of iron available for assimilatory purposes. These results demonstrate the ability of transcript analysis to reveal previously unsuspected aspects of the in situ physiology of microorganisms in subsurface environments.
Novel lineages of Planctomycetes densely colonize the alkaline gut of soil‐feeding termites (Cubitermes spp.)
Authors: Köhler Tim , Stingl Ulrich , Meuser Katja , Brune Andreas
Published: February 2008

Members of the phylum Planctomycetes are found in aquatic and terrestrial habitats. Here we show that the highest density of Planctomycetes in natural environments (2.6 × 109 cells ml−1) is encountered in the hindgut of soil‐feeding termites (Cubitermes spp.), where they constitute up to one‐third of the bacteria in the alkaline P3 compartment detected by fluorescent in situ hybridization (FISH). A 16S‐rRNA‐based approach revealed that the planctomycete community is very diverse and falls into three major clusters representing novel, deeply branching lineages. Terminal restriction fragment length polymorphism (T‐RFLP) analysis and FISH with cluster‐specific oligonucleotide probes confirmed that most of the lineages are also present in other gut compartments, albeit in much lower numbers, but absent from the food soil. The majority of planctomycetes in the gut belong to a large clade, the ‘Termite planctomycete cluster’, which consists exclusively of clones from termite guts and seems to be represented in all termite species.
Resilience of the rhizosphere Pseudomonas and ammonia‐oxidizing bacterial populations during phytoextraction of heavy metal polluted soil with poplar
Authors: Frey Beat , Pesaro Manuel , Rüdt Andreas , Widmer Franco
Published: February 2008

We assessed the effects of phytoextraction on the dynamics of Pseudomonas spp. and ammonia‐oxidizing bacterial populations in a heavy metal (HM) polluted soil. Hybrid poplars were grown in two‐compartment root containers with a medium history (> 4 years) of HM pollution for 13 weeks. Bulk and poplar rhizosphere soils were analysed by denaturing gradient gel electrophoresis (DGGE) of Pseudomonas (sensu stricto) 16S rRNA and amoA gene fragments. DGGE patterns revealed that Pseudomonas and amoA‐containing populations in the contaminated soils were markedly different from those in the uncontaminated soils. Pseudomonas and amoA profiles appeared to be stable over time in the bulk soils. In contrast, contaminated rhizosphere soils revealed a clear shift of populations with removal of HM becoming similar or at least shifted to the populations of the uncontaminated soils. The effect of phytoextraction was, however, not evident in the bulk samples, which still contained large amounts of HM. Cloning and sequencing of dominant DGGE bands revealed that Pseudomonas were phylogenetically related to the Pseudomonas fluorescens cluster and the amoA sequences to Nitrosospira spp. At the last sampling, major prominent band sequences from contaminated rhizosphere soils were identical to sequences obtained from uncontaminated rhizosphere soils, indicating that the populations were dominated by the same phylotypes. This study suggests that two taxonomically different populations are able to recover after the relief of HM stress by phytoextraction practices, whereas bulk microbial activities still remained depressed.