bluuebunny/crossref_metadata_2025 huggingface dataset:
Revealing genes associated with vitellogenesis in the liver of the zebrafish (Danio rerio) by transcriptome profiling
Authors: Levi Liraz , Pekarski Irena , Gutman Ellen , Fortina Paolo , Hyslop Terry , Biran Jakob , Levavi-Sivan Berta , Lubzens Esther
Published: March 2009

Background

In oviparous vertebrates, including fish, vitellogenesis consists of highly regulated pathways involving 17β-estradiol (E2). Previous studies focused on a relatively small number of hepatic expressed genes during vitellogenesis. This study aims to identify hepatic genes involved in vitellogenesis and regulated by E2, by using zebrafish microarray gene expression profiling, and to provide information on functional distinctive genes expressed in the liver of a vitellogenic female, using zebrafish as a model fish.

Results

Genes associated with vitellogenesis were revealed by the following paired t-tests (SAM) comparisons: a) two-month old vitellogenic (Vit2) females were compared with non-vitellogenic (NV) females, showing 825 differentially expressed transcripts during early stages of vitellogenesis, b) four-month old vitellogenic (Vit4) females were compared with NV females, showing 1,046 differentially expressed transcripts during vitellogenesis and c) E2-treated males were compared with control males, showing 1,828 differentially expressed transcripts regulated by E2. A Venn diagram revealed 822 common transcripts in the three groups, indicating that these transcripts were involved in vitellogenesis and putatively regulated by E2. In addition, 431 transcripts were differentially expressed in Vit2 and Vit4 females but not in E2-treated males, indicating that they were putatively not up-regulated by E2. Correspondence analysis showed high similarity in expression profiles of Vit2 with Vit4 and of NV females with control males. The E2-treated males differed from the other groups. The repertoire of genes putatively regulated by E2 in vitellogenic females included genes associated with protein synthesis and reproduction. Genes associated with the immune system processes and biological adhesion, were among the genes that were putatively not regulated by E2. E2-treated males expressed a large array of transcripts that were not associated with vitellogenesis.

The study revealed several genes that were not reported before as being regulated by E2. Also, the hepatic expression of several genes was reported here for the first time.

Conclusion

Gene expression profiling of liver samples revealed 1,046 differentially expressed transcripts during vitellogenesis of which at least ~64% were regulated by E2. The results raise the question on the regulation pattern and temporal pleiotropic expression of hepatic genes in vitellogenic females.
Investigation into pedestrian exposure to near-vehicle exhaust emissions
Authors: Buzzard Neil A , Clark Nigel N , Guffey Steven E
Published: March 2009

Background

Inhalation of diesel particulate matter (DPM) is known to have a negative impact on human health. Consequently, there are regulations and standards that limit the maximum concentrations to which persons may be exposed and the maximum concentrations allowed in the ambient air. However, these standards consider steady exposure over large spatial and time scales. Due to the nature of many vehicle exhaust systems, pedestrians in close proximity to a vehicle's tailpipe may experience events where diesel particulate matter concentrations are high enough to cause acute health effects for brief periods of time.

Methods

In order to quantify these exposure events, instruments which measure specific exhaust constituent concentrations were placed near a roadway and connected to the mouth of a mannequin used as a pedestrian surrogate. By measuring concentrations at the mannequin's mouth during drive-by events with a late model diesel truck, a representative estimate of the exhaust constituent concentrations to which a pedestrian may be exposed was obtained. Typical breathing rates were then multiplied by the measured concentrations to determine the mass of pollutant inhaled.

Results

The average concentration of diesel particulate matter measured over the duration of a single drive-by test often exceeded the low concentrations used in human clinical studies which are known to cause acute health effects. It was also observed that higher concentrations of diesel particulate matter were measured at the height of a stroller than were measured at the mouth of a mannequin.

Conclusion

Diesel particulate matter concentrations during drive-by incidents easily reach or exceed the low concentrations that can cause acute health effects for brief periods of time. For the case of a particularly well-tuned late-model year vehicle, the mass of particulate matter inhaled during a drive-by incident is small compared to the mass inhaled daily at ambient conditions. On a per breath basis, however, the mass of particulate matter inhaled is large compared to the mass inhaled at ambient conditions. Finally, it was determined that children, infants, or people breathing at heights similar to that of a passing vehicle's tailpipe may be exposed to higher concentrations of particulate matter than those breathing at higher locations, such as adults standing up.
Patterns of cell proliferation and apoptosis by topographic region in normal Bos taurus vs. Bos indicus crossbreeds bovine placentae during pregnancy
Authors: Facciotti Patricia R , Rici Rose EG , Maria Durvanei A , Bertolini Marcelo , Ambrósio Carlos E , Miglino Maria A
Published: March 2009

Background

Placental and fetal growth requires high rates of cellular turnover and differentiation, which contributes to conceptus development. The trophoblast has unique properties and a wide range of metabolic, endocrine and angiogenic functions, but the proliferative profile of the bovine placenta characterized by flow cytometry analysis and its role in fetal development are currently uncharacterized. Complete understanding of placental apoptotic and proliferative rates may be relevant to development, especially if related to the pathogenesis of pregnancy losses and placental abnormalities.

Methods

In this study, the proliferation activity and apoptosis in different regions of normal bovine placenta (central and boundary regions of placentomes, placentomal fusion, microplacentomes, and interplacentomal regions), from distinct gestation periods (Days 70 to 290 of pregnancy), were analyzed by flow cytometry.

Results

Our results indicated that microplacentomes presented a lower number of apoptotic cells throughout pregnancy, with a higher proliferative activity by the end of gestation, suggesting that such structures do not contribute significantly to normal of placental functions and conceptus development during pregnancy. The placentome edges revealed a higher number of apoptotic cells from Day 170 on, which suggests that placentome detachment may well initiate in this region.

Conclusion

Variations involving proliferation and apoptotic rates may influence placental maturation and detachment, compromising placental functions and leading to fetal stress, abnormalities in development and abortion, as frequently seen in bovine pregnancies from in vitro fertilization and cloning procedures. Our findings describing the pattern of cell proliferation and apoptosis in normal bovine pregnancies may be useful for unraveling some of the developmental deviations seen in nature and after in vitro embryo manipulations.
International and indigenous diagnoses of mental disorder among Vietnamese living in Vietnam and Australia
Authors: Steel Zachary , Silove Derrick , Giao Nguyen Mong , Phan Thuy Thi Bich , Chey Tien , Whelan Anna , Bauman Adrian , Bryant Richard A.
Published: March 2009

Background

Whether the prevalence rates of common mental disorders can be compared across countries depends on the cultural validity of the diagnostic measures used.

Aims

To investigate the prevalence of Western and indigenously defined mental disorders among Vietnamese living in Vietnam and in Australia, comparing the data with an Australian-born sample.

Method

Comparative analysis of three multistage population surveys, including samples drawn from a community living in the Mekong Delta region of Vietnam (n=3039), Vietnamese immigrants residing in New South Wales, Australia (n=1161), and an Australian-born population (n=7961). Western-defined mental disorders were assessed by the Composite International Diagnostic Interview (CIDI) 2.0 and included DSM–IV anxiety, mood and substance use disorders as well as the ICD–10 category of neurasthenia. The Vietnamese surveys also applied the indigenously based Phan Vietnamese Psychiatric Scale (PVPS). Functional impairment and service use were assessed.

Results

The prevalence of CIDI mental disorders for Mekong Delta Vietnamese was 1.8% compared with 6.1% for Australian Vietnamese and 16.7% for Australians. Inclusion of PVPS mental disorders increased the prevalence rates to 8.8% for Mekong Delta Vietnamese and 11.7% for Australian Vietnamese. Concordance was moderate to good between the CIDI and the PVPS for Australian Vietnamese (area under the curve (AUC)=0.77) but low for Mekong Vietnamese (AUC=0.59). PVPS- and CIDI-defined mental disorders were associated with similar levels of functional impairment.

Conclusions

Cultural factors in the expression of mental distress may influence the prevalence rates of mental disorders reported across countries. The findings have implications for assessing mental health needs at an international level.
Impact of a mental health teaching programme on adolescents
Authors: Naylor Paul B. , Cowie Helen A. , Walters Stephen J. , Talamelli Lorenzo , Dawkins Judith
Published: March 2009

Background

Child and adolescent mental health disorders are present in around 10% of the population. Research indicates that many young people possess negative attitudes towards mental health difficulties among peers.

Aims

To assess the impact of a mental health teaching programme on adolescent pupils' understanding.

Method

Two-group pre-test–post-test control group study in two English secondary schools. Experimental classes (School E) received a six-lesson teaching intervention on mental health; control classes (School C) did not. Participants were 14- and 15-year-old pupils. The intervention consisted of six lessons on mental health issues common to young people: stress; depression; suicide/self-harm; eating disorders; being bullied; and intellectual disability. School C was given access to these lesson plans and materials on completion of the study. Understanding was measured at two time points, Time 1 (T1) and Time 2 (T2), 8 months apart, by a Mental Health Questionnaire. Behavioural, emotional and relationship strengths and difficulties were measured by the self-rated Strengths and Difficulties Questionnaire (SDQ) with five subscales: hyperactivity, emotional symptoms, conduct problems, peer problems and prosocial behaviour.

Results

AtT2, pupils in School E compared with those in School C showed significantly more sensitivity and empathy towards people with mental health difficulties. They also used significantly fewer pejorative expressions to describe mental health difficulties. There was a significant reduction in SDQ scores on conduct problems and a significant increase on prosocial behaviour among School E pupils compared with controls. Pupils valued the intervention highly, in particular the lessons on suicide/self-harm.

Conclusions

Teaching 14- and 15-year-olds about mental health difficulties helps to reduce stigma by increasing knowledge and promoting positive attitudes. The intervention also reduced self-reported conduct problems and increased prosocial behaviour. Generally, participating pupils were positive about the importance of lessons on mental health, and said that they had learnt much about the lesson topics.
Using the Stroop task to investigate the neural correlates of symptom change in schizophrenia
Authors: Krabbendam Lydia , O'Daly Owen , Morley Lucy A. , van Os Jim , Murray Robin M. , Shergill Sukhwinder S.
Published: March 2009

This study examined brain activation during a cognitive inhibition task in patients with schizophrenia following changes in their positive symptoms. A Stroop task was used during functional magnetic resonance imaging in 11 patients with schizophrenia (patient group) and 9 healthy volunteers (control group). At baseline, the patient group showed significantly attenuated activation within the anterior cingulate gyrus, left pre-/postcentral gyrus and inferior frontal junction. At follow-up, there was a significant increase in activation in the left inferior frontal junction associated with a decrease in positive symptoms, suggesting this region plays a role in the development of these symptoms.
Frontotemporal dementia presenting as schizophrenia-like psychosis in young people: clinicopathological series and review of cases
Authors: Velakoulis D. , Walterfang M. , Mocellin R. , Pantelis C. , McLean C.
Published: March 2009

Background

Few studies have investigated the relationship between schizophrenia and frontotemporal dementia.

Aims

To investigate this relationship through a clinicopathological investigation of young-onset frontotemporal dementia and a review of the case literature.

Method

Cases of young-onset frontotemporal dementia were identified within the local brain bank. The clinical course and pathological findings were collated. For the literature review, cases of frontotemporal dementia identified through Medline were selected according to defined criteria. The demographic, clinical, pathological and genetic characteristics of cases presenting with a psychotic illness were identified.

Results

In the case series, 5 of 17 patients with frontotemporal dementia had presented with a psychotic illness (schizophrenia/schizoaffective disordern=4, bipolar disordern=1) an average of 5 years prior to the dementia diagnosis. Patients with schizophrenia exhibited changes consistent with TDP-43 and ubiquitin-positive frontotemporal dementia. In the cases review, a third of patients aged 30 years or under and a quarter of those aged 40 years or under had been diagnosed with psychosis at presentation.

Conclusions

Patients with young-onset frontotemporal dementia may be diagnosed with a psychotic illness years before the dementia diagnosis is made. These findings have implications for clinicians and for our further understanding of the neurobiology of psychotic illness.
Goodbye OSCE, hello CASC: a mock CASC course and examination
Authors: Whelan Paul , Lawrence-Smith Geoffrey , Church Laurence , Woolcock Claire , Meerten Maja , Rao Ranga
Published: March 2009

The Clinical Assessment of Skills and Competencies (CASC) is the latest change to the MRCPsych examination. the CASC is a complex version of an Observed Structured Clinical Examination (OSCE) format, with paired stations, and is now the only clinical component in the MRCPsych examination. We describe how to organise a relatively inexpensive and workforce-light 1-day course and mock CASC examination by adapting a previously described method for running an OSCE workshop. We also evaluate the acceptability to trainees of a mock CASC examination and course, and describe their views on this new clinical examination format.
Grade and Stage at Presentation Do Not Predict Mortality in Patients With Bladder Cancer Who Survive Their Disease
Authors: Messing Edward M. , Madeb Ralph , Feng Changyong , Stephenson Laura , Gilchrist Kennedy W. , Young Terry , Gee Jason
Published: March 2009

Purpose

Our goal was to determine whether presenting grade and stage of bladder cancer (BC), which directly affect disease-specific survival, also influence time to and cause of non-BC deaths.

Methods

Histology slides of all men who lived in Wisconsin age ≥ 50 years diagnosed with BC in 1988 were reviewed centrally, and time and cause of death as reported to the state's tumor registry were recorded. Competing risks analyses based on grade, tumor stage, and age at diagnosis were generated to correlate time and causes of death (BC or non-BC) with tumor histology and age at presentation.

Results

Grade-stage categories were assigned to 509 patients with BC as follows: LGN = low grade (grade 1 or 2), nonmuscle invading (stage Ta or T1); HGN = high grade (grade 3 or carcinoma in situ), nonmucle invading (stage Ta, T1, or TIS); and INV = any grade, muscle invasive (≥ stage T2). Three hundred nine patients (60.7%) were LGN, 80 (15.7%) were HGN, and 120 (23.6%) were INV. Grade-stage category predicted overall (P = .0001) and BC-specific (P < .0001) mortality but not non-BC mortality (P = .72), with hazard ratios of 1.095 (95% CI, 0.783 to 1.531) for HGN versus LGN, 1.137 (95% CI, 0.799 to 1.617) for INV versus LGN, and 1.038 (95% CI, 0.670 to 1.607) for INV versus HGN. Age had a highly significant effect on overall and non-BC deaths (P < .0001) but only marginally predicted BC deaths (P = .054). Time to non-BC death did not differ significantly between grade-stage category (P = .12) or cause of death (P = .81).

Conclusion

Grade-stage category at diagnosis predicts overall and BC mortality but not mortality from other causes. Thus, particularly for INV disease, because BC represents the major threat to life, aggressive therapies that have been shown to be effective are justified.
Feasibility Trial of Partial Breast Irradiation With Concurrent Dose-Dense Doxorubicin and Cyclophosphamide in Early-Stage Breast Cancer
Authors: Zellars Richard C. , Stearns Vered , Frassica Deborah , Asrari Fariba , Tsangaris Theodore , Myers Lee , DiPasquale Shirley , Lange Julie R. , Jacobs Lisa K. , Emens Leisha A. , Armstrong Deborah K. , Fetting John H. , Garrett-Mayer Elizabeth , Davidson Nancy E. , Wolff Antonio C.
Published: March 2009

Purpose

Anthracyclines and concurrent whole-breast irradiation result in prohibitive cutaneous toxicity. We hypothesized that anthracycline-based chemotherapy and concurrent partial breast irradiation (PBI) is safe and conducted a single-arm feasibility trial testing this hypothesis with dose-dense doxorubicin and cyclophosphamide (ddAC).

Patients and Methods

Women with T1-2, N0-1 breast cancer with ≥ 3 mm lumpectomy margins received PBI (40.5 Gy, 15 daily 2.7-Gy fractions) concurrently with the first two of four cycles of ddAC (60 and 600 mg/m2 of doxorubicin and cyclophosphamide, respectively, every 14 days with colony-stimulating support). Primary end points were local and systemic toxicity. Additional systemic therapy was given at the physician's discretion.

Results

Twenty-seven patients enrolled between November 2004 and January 2007, but two patients did not receive protocol therapy (one found with additional local disease and one withdrew consent). Twenty-five women completed all planned PBI. Four (16%) of 25 did not complete all ddAC (febrile neutropenia [FN], n = 2; diverticulitis and neutropenia, n = 1; and social/economic reasons, n = 1). Four among the remaining 21 who completed all ddAC had a cycle delayed (FN, n = 1; acute respiratory illness, n = 1; foot blisters, n = 1; perianal dermatitis, n = 1). There was no grade 3 to 4 anemia or thrombocytopenia. Grade 3 nonhematologic toxicities (none grade 4) occurred in 28% (seven of 25) of patients (nausea/vomiting, n = 3; stomatitis, n = 2; contralateral breast abscess, n = 1; fatigue, n = 1; and cough/bronchospasms, n = 1). The observed rate of ≥ grade 2 skin toxicity was 0% (0 of 25; one-sided 95% CI, 0% to 11%).

Conclusion

PBI with concurrent ddAC is feasible, and local/systemic toxicity is acceptable. Larger studies are warranted to assess long-term locoregional control and late toxicities.
Identification of SYWKQCAFNAVSCFamide: a broadly conserved crustacean C-type allatostatin-like peptide with both neuromodulatory and cardioactive properties
Authors: Dickinson Patsy S. , Wiwatpanit Teerawat , Gabranski Emily R. , Ackerman Rachel J. , Stevens Jake S. , Cashman Christopher R. , Stemmler Elizabeth A. , Christie Andrew E.
Published: March 2009

The allatostatins comprise three structurally distinct peptide families that regulate juvenile hormone production by the insect corpora allata. A-type family members contain the C-terminal motif –YXFGLamide and have been found in species from numerous arthropod taxa. Members of the B-type family exhibit a –WX6Wamide C-terminus and, like the A-type peptides, appear to be broadly conserved within the Arthropoda. By contrast, members of the C-type family, typified by the unblocked C-terminus–PISCF, a pyroglutamine blocked N-terminus, and a disulfide bridge between two internal Cys residues, have only been found in holometabolous insects, i.e. lepidopterans and dipterans. Here, using transcriptomics, we have identified SYWKQCAFNAVSCFamide (disulfide bridging predicted between the two Cys residues), a known honeybee and water flea C-type-like peptide, from the American lobster Homarus americanus (infraorder Astacidea). Using matrix assisted laser desorption/ionization Fourier transform mass spectrometry (MALDI-FTMS), a mass corresponding to that of SYWKQCAFNAVSCFamide was detected in the H. americanus brain, supporting the existence of this peptide and its theorized structure. Furthermore, SYWKQCAFNAVSCFamide was detected by MALDI-FTMS in neural tissues from five additional astacideans as well as 19 members of four other decapod infraorders (i.e. Achelata, Anomura,Brachyura and Thalassinidea), suggesting that it is a broadly conserved decapod peptide. In H. americanus, SYWKQCAFNAVSCFamide is capable of modulating the output of both the pyloric circuit of the stomatogastric nervous system and the heart. This is the first demonstration of bioactivity for this peptide in any species.
Bursectomy compared with acromioplasty in the management of subacromial impingement syndrome
Authors: Henkus H. E. , de Witte P. B. , Nelissen R. G. H. H. , Brand R. , van Arkel E. R. A.
Published: March 2009

In a prospective randomised study we compared the results of arthroscopic subacromial bursectomy alone with debridement of the subacromial bursa followed by acromioplasty. A total of 57 patients with a mean age of 47 years (31 to 60) suffering from primary subacromial impingement without a rupture of the rotator cuff who had failed previous conservative treatment were entered into the trial. The type of acromion was classified according to Bigliani. Patients were assessed at follow-up using the Constant score, the simple shoulder test and visual analogue scores for pain and functional impairment. One patient was lost to follow-up.

At a mean follow-up of 2.5 years (1 to 5) both bursectomy and acromioplasty gave good clinical results. No statistically significant differences were found between the two treatments. The type of acromion and severity of symptoms had a greater influence on the clinical outcome than the type of treatment. As a result, we believe that primary subacromial impingement syndrome is largely an intrinsic degenerative condition rather than an extrinsic mechanical disorder.
The incidence of the patellar clunk syndrome in a recently designed mobile-bearing posteriorly stabilised total knee replacement
Authors: Fukunaga K. , Kobayashi A. , Minoda Y. , Iwaki H. , Hashimoto Y. , Takaoka K.
Published: March 2009

The patellar clunk syndrome describes painful catching, grinding or jumping of the patella when the knee moves from a flexed to an extended position after total knee replacement (TKR). The posterior stabilised TKR had been noted to have a higher incidence of this problem. Mobile-bearing posteriorly stabilised TKRs have been introduced to improve patellar tracking and related problems by a mechanism of self-alignment. We evaluated the patellar clunk syndrome in 113 knees in 93 patients with such a TKR at a mean follow-up of 2.3 years (2.0 to 3.2). The syndrome was identified in 15 knees (13.3%).

Logistic regression analysis showed that the absolute value of the post-operative angle of patellar tilt was significantly associated with the occurrence of patellar clunk (p = 0.025). Patellar tracking should be carefully checked during surgery.
Delayed presentation of carotid artery dissection following major orthopaedic trauma resulting in dense hemiparesis
Authors: Edmundson S. P. , Hirpara K. M. , Ryan R. S. , O’Malley T. , O’Grady P.
Published: March 2009

We report a 30-year-old patient who was involved in a high-velocity road traffic accident and developed a left-sided hemiparesis, which was noted in the post-operative period following bilateral femoral intramedullary nailing. CT scanning of the brain revealed infarcts in the right frontal and parietal lobes in the distribution of the right middle cerebral artery. CT angiography showed occlusion of the right internal carotid artery consistent with internal carotid artery dissection. He was anticoagulated and nine months later was able to walk independently.

An awareness of this injury is needed to diagnose blunt trauma to the internal carotid artery. Even in the absence of obvious neck trauma, carotid artery dissection should be suspected in patients with a neurological deficit in the peri-operative period.
Can Birthweight Discordancy Within Monozygotic Twin Pairs Be Used as an Indicator of Chorionicity?
Authors: Gielen Marij , Derom Catherine , Derom Robert , Vlietinck Robert , Zeegers Maurice P.
Published: March 2009

Both zygosity and chorionicity provide important information in twin research. The East Flanders Prospective Twin Survey (EFPTS) determines zygosity and chorionicity at birth and therefore provides a gold standard for the testing of diagnostic parameters that can be used to determine chorionicity. The aim of the present study was to investigate whether birthweight discordancy can be used as an indicator of chorionicity. The study sample consisted of 4,060 live-born twin pairs from the EFPTS. We studied MZ twins, using univariate and multivariate logistic regression analyses to calculate odds ratios (OR) and 95% confidence intervals (CI) of being MC in relation to discordancy level. Diagnostic parameters, including sensitivity and specificity, were calculated. A two-fold cross-validation was carried out and a bootstrap distribution with 10,000 samples was created to estimate the standard deviations. For discordancy levels of below 10%, 10–15%, 15–20%, 20–25% and above 25%, the ORs (95% CI) were 1.16 (0.91–1.47), 1.38 (1.05–1.80), 2.13 (1.51–3.01), 2.73 (1.73–4.29) and 2.81 (2.81–4.35) respectively. There were no gender differences. Sensitivity was 42.2% (SD 5.6%), specificity was 72.8% (SD 6.3%), positive predictive value was 72.8% (1.5%) and the negative predictive value was 39.2% (0.7%). In conclusion, although a higher discordancy level resulted in higher ORs of being an MC twin, birthweight discordancy level can only be used to some weak extent as a proxy for chorionicity, highlighting the need to assess and record chorionicity data in obstetrical units.
Molecular interactions within the plant TOC complex
Authors: Sommer Maik S. , Schleiff Enrico
Published: March 2009

Protein transport, especially into different cellular compartments, is a highly coordinated and regulated process. The molecular machineries which carry out these transport processes are highly complex in structure, function, and regulation. In the case of chloroplasts, thousands of protein molecules have been estimated to be transported across the double-membrane bound envelope per minute. In this brief review, we summarize current knowledge about the molecular interplay during precursor protein import into chloroplasts, focusing on the initial events at the outer envelope.
Precise Gene-Dose Alleles for Chemical Genetics
Authors: Yan Zhun , Berbenetz Nicolas M , Giaever Guri , Nislow Corey
Published: March 2009

Modulating gene dose is an effective way to alter protein levels and modify phenotypes to understand gene function. In addition, combining gene-dose alleles with chemical perturbation can provide insight into drug–gene interactions. Here, we present a strategy that combines diverse loss-of-function alleles to systematically modulate gene dose in Saccharomyces cerevisiae. The generated gene dosage allele set expands the genetic toolkit for uncovering novel phenotypes.
Species–energy theory, pulsed resources, and regulation of avian richness during a mountain pine beetle outbreak
Authors: Drever Mark C. , Goheen Jacob R. , Martin Kathy
Published: March 2009

Species–energy theory provides a framework through which to link two features commonly noted in local communities: episodic production of resources (i.e., resource pulses) and the regulation of local species richness through time. We examined the pathways through which a resource pulse, a large‐scale outbreak of mountain pine beetles, was borne out in six foraging guilds comprising a forest bird community in British Columbia, Canada, 1997–2007. We investigated statistical relationships between richness and abundance in each guild to evaluate the prediction that the outbreak should be manifested in species most reliant upon bark beetles (i.e., the bark insectivore guild). We then employed randomization methods to evaluate whether the beetle outbreak obscured evidence for local regulation for the six foraging guilds. Density and richness of bark insectivores increased over the course of the outbreak. More species of bark insectivores were detected for a given number of individuals following the outbreak, consistent with an increase in the number and types of resources. Richness of bark insectivores showed no evidence of regulation. In contrast, densities of most other foraging guilds were not strongly correlated with the habitat changes resulting from the beetle outbreak and displayed only weak evidence of regulation of richness. We suggest that such weak regulation of richness may be a general feature of forest bird communities. Coupled with long‐term data, resource pulses provide exceptional opportunities through which to test predictions of species–energy theory.
Complex equilibria in the maintenance of boundaries: experiments with mussel beds
Authors: Robles Carlos D. , Desharnais Robert A. , Garza Corey , Donahue Megan J. , Martinez Carlos A.
Published: March 2009

Stationary boundaries of sedentary species may belie dynamic processes that form them. Our aim was to test an implication of an evolving body of theory, that such boundaries are manifestations of complex regulatory dynamics.

On rocky shores of British Columbia, large‐scale field experiments altered the densities of predatory sea stars (Pisaster ochraceus), causing shifts in the location of the lower vertical boundaries of their prey, sea mussels (Mytilus californianus). While control mussel beds remained unchanged, experimental reductions of sea star densities caused the downward extension of the lower boundaries, and experimental increases in sea stars densities caused the upward recession of the lower boundary well into the zone presumed to be a spatial refuge from predation. Cleared plots prepared within the initial boundaries were recolonized to varying degrees, depending on predator densities. After 30 months, plots on sea star removal sites showed high densities of adult mussels, control plots showed intermediate densities, and sea star addition plots showed only a sparse cover of alternative prey. Observations by divers at high tide showed that as small prey were depleted progressively from removal, to control, to addition sites, correspondingly larger mussels were attacked, including very large individuals comprising the lower boundary of addition sites.

The findings contradict classic theory of zonation based on static prey refuges and support an alternative theory in which boundaries are maintained by complex, spatially structured equilibria.
RELATIVE REINFORCER RATES AND MAGNITUDES DO NOT CONTROL CONCURRENT CHOICE INDEPENDENTLY
Authors: Elliffe Douglas , Davison Michael , Landon Jason
Published: March 2009

One assumption of the matching approach to choice is that different independent variables control choice independently of each other. We tested this assumption for reinforcer rate and magnitude in an extensive parametric experiment. Five pigeons responded for food reinforcement on switching‐key concurrent variable‐interval variable‐interval schedules. Across conditions, the ratios of reinforcer rates and of reinforcer magnitudes on the two alternatives were both manipulated. control by each independent variable, as measured by generalized‐matching sensitivity, changed significantly with the ratio of the other independent variable. Analyses taking the model‐comparison approach, which weighs improvement in goodness‐of‐fit against increasing number of free parameters, were inconclusive. These analyses compared a model assuming constant sensitivity to magnitude across all reinforcer‐rate ratios with two alternative models. one of those alternatives allowed sensitivity to magnitude to vary freely across reinforcer‐rate ratios, and was less efficient than the common‐sensitivity model for all pigeons, according to the schwarz‐Bayes information criterion. The second alternative model constrained sensitivity to magnitude to be equal for pairs of reinforcer‐rate ratios that deviated from unity by proportionately equal amounts but in opposite directions. This model was more efficient than the common‐magnitude‐sensitivity model for 2 of the pigeons, but not for the other 3. An analysis of variance, carried out independently of the generalized‐matching analysis, also showed a significant interaction between the effects of reinforcer rate and reinforcer magnitude on choice. On balance, these results suggest that the assumption of independence inherent in the matching approach cannot be maintained. Relative reinforcer rates and magnitudes do not control choice independently.
AN INVITATION TO BEHAVIOR ANALYSTS: REVIEW OF IN SEARCH OF MEMORY: THE EMERGENCE OF A NEW SCIENCE OF MIND BY ERIC R KANDEL
Authors: Mechner Francis
Published: March 2009

This fascinating autobiography and multifaceted case history in neuroscience research is accessible to laymen and potentially instructive to working scientists. Kandel takes the reader through his thought processes as he describes experiments that led to some of the past decades' major neuroscience discoveries (some highlights of which are summarized in the review's Appendix), and eventually to his Nobel Prize. The review analyzes some of the terminological and conceptual issues that have often inhibited communication between behavior analysts and neuroscientists, with special attention to some of Bennett and Hacker's admonitions viewed from the perspective of language evolution and linguistics. The review then discusses opportunities for behavior analysts to collaborate with neuroscientists by applying behavioral contingency analysis to help specify the independent variables of neuroscience experiments described by Kandel. Finally, it examines Kandel's provocative heuristics for locating important research problems, and the lessons that can be gleaned from the book regarding the attributes of potentially great achievers.
Bone Response to Loaded Implants With Non‐Matching Implant‐Abutment Diameters in the Canine Mandible
Authors: Cochran David L. , Bosshardt Dieter D. , Grize Leticia , Higginbottom Frank L. , Jones Archie A. , Jung Ronald E. , Wieland Marco , Dard Michel
Published: March 2009

Background: One way to evaluate various implant restorations is to measure the amount of bone change that occurs at the crestal bone. The objective of this study was to histologically evaluate the alveolar bone change around a bone‐level, non‐matching implant‐abutment diameter configuration that incorporated a horizontal offset and a Morse taper internal connection.

Methods: The study design included extraction of all mandibular premolars and first molars in five canines. After 3 months, 12 dental implants were placed at three levels in each dog: even with the alveolar crest, 1 mm above the alveolar crest, and 1 mm below the alveolar crest. The implants were submerged on one side of the mandible. On the other side, healing abutments were exposed to the oral cavity (non‐submerged). Gold crowns were attached 2 months after implant placement. The dogs were sacrificed 6 months postloading, and specimens were processed for histologic and histometric analyses.

Results: Evaluation of the specimens indicated that the marginal bone remained near the top of the implants under submerged and non‐submerged conditions. The amount of bone change for submerged implants placed even with, 1 mm below, and 1 mm above the alveolar crest was −0.34, −1.29, and 0.04 mm, respectively (negative values indicate bone loss). For non‐submerged implants, the respective values were −0.38, −1.13, and 0.19 mm. For submerged and non‐submerged implants, there were significant differences in the amount of bone change among the three groups (P <0.05). The percentage of bone‐to‐implant contact for submerged implants was 73.3%, 71.8%, and 71.5%. For non‐submerged implants, the respective numbers were 73.2%, 74.5%, and 76%. No significant differences occurred with regard to the percentage of bone contact.

Conclusions: Minimal histologic bone loss occurred when dental implants with non‐matching implant‐abutment diameters were placed at the bone crest and were loaded for 6 months in the canine. The bone loss was significantly less (five‐ to six‐fold) than that reported for bone‐level implants with matching implant‐abutment diameters (butt‐joint connections).
Evaluation of the effects of transvenous pacing site on left ventricular function and synchrony in healthy anesthetized dogs
Authors: Maisenbacher Herbert W. , Estrada Amara H. , Prošek Robert , Shih Andre C. , VanGilder James M.
Published: March 2009

Objective—To compare the acute effects of cardiac pacing from various transvenous pacing sites on left ventricular (LV) function and synchrony in clinically normal dogs.

Animals—10 healthy adult mixed-breed dogs.

Procedures—Dogs were anesthetized, and dual-chamber transvenous biventricular pacing systems were implanted. Dogs were paced in single-chamber mode from the right atrial appendage (RAA) alone and in dual-chamber mode from the right ventricular apex (RVA), from the left ventricular free wall (LVFW), and simultaneously from the RVA and LVFW (BiV). Standard ECG and echocardiographic measurements, cardiac output measured with the lithium dilution method (LiDCO), and tissue Doppler–derived measurements of LV synchrony were obtained during each of the pacing configurations.

Results—Placement of the biventricular pacing systems was possible in 8 of the 10 dogs. The QRS duration was significantly different among all pacing sites, and the order of increasing duration was RAA, BiV, LVFW, and RVA. Pacing sites did not differ with respect to fractional shortening; however, pacing from the RVA resulted in a significantly lower ejection fraction than pacing from all other sites. During RVA and LVFW pacing, LiDCO was significantly lower than that at other sites; there was no significant difference between RAA and BiV pacing with respect to LiDCO. Although the degree of dyssynchrony was significantly lower during pacing from the RAA versus other ventricular pacing sites, it was not significantly different among sites.

Conclusions and Clinical Relevance—Ventricular activation by RAA pacing provided the best LV function and synchrony. Pacing from the RVA worsened LV function, and although pacing from the LVFW improved it, BiV pacing may provide additional improvement.
Effect of subcutaneous administration of a killed Mycobacterium avium subsp paratuberculosis vaccine on colonization of tissues following oral exposure to the organism in calves
Authors: Sweeney Raymond W. , Whitlock Robert H. , Bowersock Terry L. , Cleary Diane L. , Meinert Todd R. , Habecker Perry L. , Pruitt Greg W.
Published: March 2009

Objective—To evaluate the effect of vaccination of calves with a killed Mycobacterium avium subsp paratuberculosis (MAP) vaccine on colonization of tissues following oral MAP exposure.

Animals—12 healthy Holstein calves.

Procedures—At 14 days after birth, calves received the MAP vaccine (1.0 mL, SC) or saline (0.9% NaCl) solution (1.0 mL, SC [control treatment]). Each calf received 1.2 × 109 CFUs of live MAP orally 21 and 22 days after vaccination. Prior to vaccination and at subsequent intervals, a blood sample was collected for ELISA detection of antibodies against MAP and for whole blood, antigen-specific, interferon (IFN)-γ–release assay. Nine weeks after MAP challenge, calves were euthanized and various tissue samples were collected for mycobacterial culture. Interferon-γ production in prescapular lymph node cells was measured following in vitro stimulation with MAP antigens.

Results—Calves were seronegative for anti-MAP antibodies at all times. Compared with the findings in control calves, antigen-specific IFN-γ production in circulating lymphocytes and prescapular lymph node cells from vaccinated calves was significantly higher. Culture of tissues from vaccinated calves yielded significantly fewer CFUs of MAP (2,417 CFUs/g), compared with tissues from control calves (15,709 CFUs/g). Furthermore, significantly fewer tissue samples from vaccinated calves yielded MAP in culture (21.8 tissues/calf), compared with findings in control calves (27.6 tissues/calf).

Conclusions and Clinical Relevance—Inoculation of calves with a killed MAP vaccine was associated with reduced colonization of intestinal tissues following experimental exposure to MAP. Use of the vaccine could potentially reduce transmission of MAP to calves in infected herds.
Les paradoxes d'une satisfaction
Authors: Baudelot Christian , Serre Delphine
Published: March 2009

Résumé Lorsqu’on demande aux femmes si elles sont satisfaites de leur salaire, compte tenu du travail qu’elles fournissent, leurs réponses diffèrent à peine de celles des hommes alors que leurs salaires sont inférieurs de 20 %. Le paradoxe s’explique dès lors qu’on prend en compte le poids de la représentation du salaire féminin comme salaire d’appoint et que l’on cherche à comprendre les points de référence qui servent aux unes et aux autres pour évaluer leur salaire. C’est en comparant leurs salaires à ceux de leurs supérieurs immédiats ou de leurs collègues masculins que les hommes expriment leur satisfaction ou insatisfaction, alors que c’est en mesurant le chemin parcouru depuis la génération de leurs mères et en comparant leurs salaires à ceux d’autres femmes souvent moins bien payées que les femmes évaluent le niveau de satisfaction qu’elles retirent de leur travail et de leur salaire.
Le choc du licenciement : femmes et hommes dans la tourmente
Authors: Trotzier Christian
Published: March 2009

Résumé Deux enquêtes de terrain ont été conduites, l’une en 1999, l’autre entre 2003 et 2005, auprès d’ouvrières et d’ouvriers licencié-e-s en 1979 et 1983 dans le cadre de réductions d’effectifs. Le caractère sélectif de l’exclusion génère de forts sentiments d’injustice et d’humiliation que l’on ne retrouve pas dans le cas d’une fermeture d’établissement. Le désarroi qui suit le licenciement, lié principalement à l’estimation des perspectives d’emploi, apparaît plus fréquemment chez les femmes. Les troubles de la santé qui surgissent sont spécifiques à chaque sexe. Chez les femmes, des états dépressifs s’installent sur le long terme. La vulnérabilité sociale enclenchée par le licenciement se ponctue, chez les hommes, par une surmortalité. Le capital collectif est détruit. La défiance définitive des licencié-e-s envers le syndicalisme en est un aspect. Le sentiment d’injustice se vit dans la solitude. Il nourrit le ressentiment. La violence des licenciements apparaît ici comme une violence cachée.
Declined neural efficiency in cognitively stable human immunodeficiency virus patients
Authors: Ernst Thomas , Yakupov Renat , Nakama Helenna , Crocket Grace , Cole Michael , Watters Michael , Ricardo‐Dukelow Mary Lynn , Chang Linda
Published: March 2009

Objective

To determine whether brain activation changes in clinically and neurocognitively normal human immunodeficiency virus (HIV)–infected and in HIV‐seronegative control (SN) participants over a 1‐year period.

Methods

Functional magnetic resonance imaging (fMRI) was performed in 32 SN and 31 HIV patients (all with stable combination antiretroviral treatment) at baseline and after 1 year. Each participant performed a set of visual attention tasks with increasing attentional load (from tracking two, three, or four balls). All HIV and SN participants had normal neuropsychological function at both examinations.

Results

Over 1 year, HIV patients showed no change in their neurocognitive status or in task performance during fMRI. However, HIV patients showed significant 1‐year increases in fMRI signals in the prefrontal and posterior parietal cortices for the more difficult tasks, whereas SN control participants showed only decreases in brain activation in these regions. This resulted in significant interactions between HIV status and time of study in left insula, left parietal, left temporal, and several frontal regions (left and right middle frontal gyrus, and anterior cingulate).

Interpretation

Because fMRI task performance remained unchanged in both groups, the HIV patients appeared to maintain performance by increasing usage of the attention network, whereas the control participants reduced usage of the attention network after 1 year. These findings suggest improved efficiency or a practice effect in the SN participants but declined efficiency of the neural substrate in HIV patients, possibly because of ongoing brain injury associated with the HIV infection, despite their apparent stable clinical course. Ann Neurol 2009;65:316–325
Does knee malalignment increase the risk of development and progression of knee osteoarthritis? A systematic review
Authors: Tanamas Stephanie , Hanna Fahad S. , Cicuttini Flavia M. , Wluka Anita E. , Berry Patricia , Urquhart Donna M.
Published: March 2009

Objective

To systematically review the evidence for a relationship between malalignment of the knee joint and progression and/or development of knee osteoarthritis (OA).

Methods

Electronic searches of Medline, EMBase, and CINAHL were performed up to July 2008 using medical subject headings and free‐text words. We included radiographic or magnetic resonance imaging (MRI) studies that met a set of predefined criteria. Two independent reviewers extracted the data and assessed the methodologic quality of the selected studies. Due to both heterogeneity and a limited number of studies, the results were summarized using a best evidence synthesis.

Results

Fourteen studies met our inclusion criteria and 8 were considered high quality. We found limited evidence for an association between knee malalignment and incident knee OA, because only 1 cohort study examined this relationship. However, there was strong evidence based on 4 high‐quality cohort studies that knee malalignment is an independent risk factor for progression of radiographic knee OA. This finding was further supported by 2 high‐quality MRI cohort studies that found a relationship between varus and valgus alignment and structural progression of knee OA.

Conclusion

Malalignment of the knee joint was found to be an independent risk factor for the progression of knee OA. Given the paucity of investigation into the relationship between knee malalignment and risk of incident OA, further high‐quality cohort studies are needed, and these may have important implications for the prevention of knee OA.