bluuebunny/crossref_metadata_2025 huggingface dataset:
Infliximab in severe active ankylosing spondylitis with spinal ankylosis
Authors: Cheung P. P. M. , Tymms K. E. , Wilson B. J. , Shadbolt B. , Brook A. S. , Dorai Raj A. K. , Khoo K. B. K.
Published: March 2008

Background:  Infliximab is an anti‐tumour necrosis factor monoclonal antibody, which significantly improves pain, stiffness and functional disability outcomes in patients with active ankylosing spondylitis. There are limited data available on the efficacy of this treatment for the subgroup with established spinal ankylosis.

Aim:  To compare the treatment response of infliximab in active severe ankylosing spondylitis for patients with and without radiographic evidence of spinal ankylosis in the clinical practice setting.

Methods:  Twenty‐seven patients with mean Bath Ankylosing Spondylitis Disease Activity Index of 8.7, all HLA‐B27 positive, with 11 (41%) having spinal ankylosis, were studied for 54 weeks. The qualification for initial and ongoing infliximab treatment was defined by the Australian Pharmaceutical Benefit Schedule (PBS), and 5 mg/kg of infliximab was given at 0 week (baseline), repeated at 2 and 6 weeks and every 6 weeks thereafter. At each time point, PBS‐mandated and international consensus response measures were completed. Disease activity and outcome measures for spinal ankylosis subgroup and those who did not have spinal ankylosis were cross‐sectionally compared at baseline and 1 year.

Results:  Patients with spinal ankylosis tended to be older (P = 0.01). Although the subgroup with spinal ankylosis had higher baseline activity scores, the only significant difference between the subgroups was the degree of morning stiffness (P = 0.04). By 54 weeks, all patients including the subgroup with spinal ankylosis fulfilled the PBS criteria for continuation of treatment. Majority of patients including the subgroup with spinal ankylosis achieved the various international consensus response measures. Patients with spinal ankylosis also experienced significant improvements in health‐related quality of life, with majority returning to full‐time employment by 1 year.

Conclusion:  In real‐life clinical practice, patients with established disease with spinal ankylosis and high levels of inflammation and disease activity can achieve a major clinical response with infliximab.
Possible peroxidase functions in the interaction between the parasitic plant,Orobanche aegyptiaca, and its host,Arabidopsis thaliana
Authors: MOR AVISHAI , MAYER ALFRED M. , LEVINE ALEX
Published: March 2008

The mechanism by which the flowering holoparasitic plant,Orobanche aegyptiaca, infects its host without evoking a defence mechanism is still poorly understood. In this work, we studied several mechanisms used by phytopathogenic fungi. We focussed on the possible role of peroxidases duringO. aegyptiacapenetration into the roots ofArabidopsis thaliana. A convenient experimental system for studying the interaction under sterile conditions was developed. The formation of extracellular reactive oxygen species (ROS) was detected at the interaction site before, during, and after the parasite penetrated into the host. These extracellular ROS probably originated from the parasite. However, no intracellular ROS could be detected at the site of the interaction. Peroxidase activity was observed mainly at the apex of the root of the parasite and in the adventitious roots of the tubercle. Benzhydroxamic acid, a peroxidase inhibitor, was used to probe the possible role of peroxidase in the infection process. Peroxidase activity was observed in the root apex and adventitious roots ofO. aegyptiaca,but no evidence was found for its participation in the actual infection process. Peroxidase activity was also found in the later stages of the interaction between the host and the parasite. We propose that peroxidases could have a role in generating extracellular ROS for loosening the cell wall of the host in order to facilitate penetration. Alternatively, the ROS could act in facilitating the root elongation of the parasite.
Biological activity of pyribenzoxim in winter wheat and associated weeds
Authors: KOO SUK J. , CASELEY JOHN C.
Published: March 2008

Pot and field tests were conducted to evaluate the efficacy of pyribenzoxim for winter weeds in wheat. In the pot tests, pyribenzoxim, at 50 g ha−1, controlled certain biotypes of blackgrass, including a fenoxaprop‐P‐ethyl‐resistant biotype (the “Notts” biotype). A chlorotoluron‐resistant blackgrass (the “Peldon” biotype) was not controlled. Cleaver, at the three‐to‐four‐leaf stage, was completely controlled by pyribenzoxim at 30 g ha−1. In the field, the application in December gave good control of common chickweed, but did not control other weeds. No damage to wheat was observed with this rate of pyribenzoxim in December. The application in March gave complete control of blackgrass, hairy chess, and soft brome at 70 g ha−1, and cleaver at 140 g ha−1. The partial control of corn poppy and field violet was achieved. The March application scorched the wheat at 50–70 g ha−1, with prolonged stunting at 100–140 g ha−1. In conclusion, it was shown that pyribenzoxim had potential as a wheat herbicide, but needed further fine‐tuning to find an optimum dosage.
Interaction of a bioherbicide and glyphosate for controlling hemp sesbania in glyphosate‐resistant soybean
Authors: BOYETTE C. DOUGLAS , HOAGLAND ROBERT E. , WEAVER MARK A.
Published: March 2008

The bioherbicidal fungus, Colletotrichum truncatum (Schwein.) Andrus & Moore, was tested at different inoculum concentrations alone and in combination with, prior to or following treatment with different rates of glyphosate (N‐[phosphonomethyl]glycine) (Roundup Ultra) for the control of hemp sesbania (Sesbania exaltata[Raf.] Rydb. ex A.W. Hill) in Roundup Ready soybean field plots. Colletotrichum truncatum and glyphosate were applied in all pair‐wise combinations of 0, 1.25, 2.5, 5.0, and 10.0 × 106 spores mL−1 (i.e. 3.125, 6.25, 12.5, and 25 × 1011 spores ha−1), and 0.15, 0.30, 0.60, and 1.2 kg ha−1, respectively. Weed control and disease incidence were enhanced at the two lowest fungal and herbicidal rates when the fungal spores were applied after glyphosate treatment. The application of the fungus in combination with or prior to glyphosate application at 0.30 kg ha−1 resulted in reduced disease incidence and weed control regardless of the inoculum's concentration. At the highest glyphosate rates, the weeds were controlled by the herbicide alone. These results suggest that it might be possible to utilize additive or synergistic herbicide and pathogen interactions to enhance hemp sesbania control.
Sensitization of meningeal nociceptors: inhibition by naproxen
Authors: Levy Dan , Zhang Xi‐Chun , Jakubowski Moshe , Burstein Rami
Published: March 2008

Migraine attacks associated with throbbing (manifestation of peripheral sensitization) and cutaneous allodynia (manifestation of central sensitization) are readily terminated by intravenous administration of a non‐selective cyclooxygenase (COX) inhibitor. Evidence that sensitization of rat central trigeminovascular neurons was also terminated in vivo by non‐selective COX inhibition has led us to propose that COX inhibitors may act centrally in the dorsal horn. In the present study, we examined whether COX inhibition can also suppress peripheral sensitization in meningeal nociceptors. Using single‐unit recording in the trigeminal ganglion in vivo, we found that intravenous infusion of naproxen, a non‐selective COX inhibitor, reversed measures of sensitization induced in meningeal nociceptors by prior exposure of the dura to inflammatory soup (IS): ongoing activity of Aδ‐ and C‐units and their response magnitude to mechanical stimulation of the dura, which were enhanced after IS, returned to baseline after naproxen infusion. Topical application of naproxen or the selective COX‐2 inhibitor N‐[2‐(cyclohexyloxy)‐4‐nitrophenyl]‐methanesulfonamide (NS‐398) onto the dural receptive field of Aδ‐ and C‐unit nociceptors also reversed the neuronal hyper‐responsiveness to mechanical stimulation of the dura. The findings suggest that local COX activity in the dura could mediate the peripheral sensitization that underlies migraine headache.
Impact of sex and hormones on new cells in the developing rat hippocampus: a novel source of sex dimorphism?
Authors: Zhang Jian‐Min , Konkle Anne T. M. , Zup Susan L. , McCarthy Margaret M.
Published: March 2008

The hippocampus is a key brain region regulating complex cognitive and emotional responses, and is implicated in the etiology of depressive and anxiety disorders, many of which exhibit some degree of sex difference. The male rat hippocampus is consistently reported to be slightly but significantly larger than the female. The majority of studies on the development of volumetric sex differences have focused on the effects of estradiol (E2), with relatively few focusing on androgens. We examined the impact of both E2 and androgens on newly born cells in the developing rat hippocampus, and report that neonatal males have significantly more 5‐bromo‐2′‐deoxyuridine‐5′‐monophosphate (BrdU)+ cells than females. Both testosterone (T) and dihydrotestosterone treatment of females significantly increased the number of BrdU+ cells, an effect blocked by the androgen receptor antagonist, flutamide. However, only T significantly increased the number of neuronal nuclear antigen+ neurons in the female rat hippocampus. Interestingly, E2 treatment also increased BrdU+ cells in females, but had no effect on neuron number. Instead, E2 and T significantly increased the number of newly born glial fibrillary acidic protein or glutamine synthetase+ glial cells in females, indicating that androgens and E2 may act independently to achieve distinct endpoints. Quantification of pyknotic cells at two different developmental time points indicates no sex difference in the number of cells dying, suggesting, but not proving, that gonadal steroids are promoting cell genesis.
The neural dynamics of timed motor tasks: evidence from a synchronization–continuation paradigm
Authors: Serrien Deborah J.
Published: March 2008

Distinct processing that integrates an accurate time scale is necessary for optimal motor behaviour. In the present study, corticocortical interactions as determined by EEG coherence were assessed in a synchronization–continuation paradigm during which subjects initially performed tapping movements in synchrony with external cues, followed by internal pacing of the target interval when the metronome was switched off. Unimanual and bimanual tasks were executed, and continuation of tapping was conducted with the same or different effector(s). The data showed an increased degree of mesial–central connectivity in the unpaced as compared to paced performance that was independent of task complexity, pointing to a general intensified demand of temporal processing when external cues are unavailable. When switching temporal information between effectors, coherence increased across the motor network. This increase depended upon preceding task complexity, and was most prominent for interhemispheric connections when performing unimanual tasks following bimanual pacing. Overall the data illustrate that timing of skilled actions can easily be transferred between effectors, although increased neural resources are required to conform to the temporal and motor constraints.
L‐type calcium channels are involved in fast endocytosis at the mouse neuromuscular junction
Authors: Perissinotti Paula P. , Tropper Bárbara Giugovaz , Uchitel Osvaldo D.
Published: March 2008

We used fluorescence microscopy of FM dyes‐labeled synaptic vesicles and electrophysiological recordings to examine the functional characteristics of vesicle recycling and study how different types of voltage‐dependent Ca2+ channels (VDCCs) regulate the coupling of exocytosis and endocytosis at mouse neuromuscular junction.

Our results demonstrate the presence of at least two different pools of recycling vesicles: a high‐probability release pool (i.e. a fast destaining vesicle pool), which is preferentially loaded during the first 5 s (250 action potentials) at 50 Hz; and a low‐probability release pool (i.e. a slow destaining vesicle pool), which is loaded during prolonged stimulation and keeps on refilling after end of stimulation.

Our results suggest that a fast recycling pool mediates neurotransmitter release when vesicle use is minimal (i.e. during brief high‐frequency stimulation), while vesicle mobilization from a reserve pool is the prevailing mechanism when the level of synaptic activity increases.

We observed that specific N‐ and L‐type VDCC blockers had no effect on evoked transmitter release upon low‐frequency stimulation (5 Hz). However, at high‐frequency stimulation (50 Hz), L‐type Ca2+ channel blocker increased FM2‐10 destaining and at the same time diminished quantal release. Furthermore, when L‐type channels were blocked, FM2‐10 loading during stimulation was diminished, while the amount of endocytosis after stimulation was increased.

Our experiments suggest that L‐type VDCCs promote endocytosis of synaptic vesicles, directing the newly formed vesicles to a high‐probability release pool where they compete against unused vesicles.
Electroconvulsive seizure restores neurogenesis and hippocampus‐dependent fear memory after disruption by irradiation
Authors: Warner‐Schmidt Jennifer L. , Madsen Torsten M. , Duman Ronald S.
Published: March 2008

Ongoing neurogenesis in the adult hippocampus is thought to play a role in learning and memory processes, and in response to antidepressant treatments. Low doses of irradiation (IRR) produce a significant long‐lasting inhibitory effect on hippocampal neurogenesis that correlates with long‐lasting behavioral deficits. Here we report that electroconvulsive seizure (ECS), which robustly increases adult neurogenesis in naïve animals, also reverses the disruption of neurogenesis produced by IRR exposure. Moreover, we find that vascular endothelial growth factor (VEGF) is an essential mediator of this effect. Expression of VEGF in the granule cell layer (GCL) of the hippocampus is decreased by IRR, and ECS administration reverses this deficit in VEGF. There is a corresponding alteration in the number of endothelial cells, which express VEGF, in the hippocampal GCL following IRR and ECS. We also find that blockade of VEGF signaling attenuates ECS‐induced proliferation, and VEGF infusion partially restores proliferation in irradiated animals. To examine the functional consequences of IRR and ECS on neurogenesis, hippocampus‐dependent contextual fear conditioning was assessed. We found that following disruption by IRR, ECS restores contextual learning to baseline levels at time points consistent with its effects on neurogenesis. These findings demonstrate that ECS, in part via induction of VEGF, can reverse long‐term neurogenesis deficits resulting from IRR, and that these effects have functional consequences on hippocampus‐dependent fear memory.
Forebrain dopamine depletion impairs motor behavior in lamprey
Authors: Thompson R. H. , Ménard A. , Pombal M. , Grillner S.
Published: March 2008

The structure of the basal ganglia appears to be conserved throughout vertebrate evolution, with characteristic cellular and transmitter components in each area, and the same types of afferent input. As described in rodents and primates, depletion of the striatal dopamine results in characteristic motor deficits. To explore if this role of the basal ganglia in modulating motor function was present early in vertebrate evolution, we investigated here the effects of striatal dopamine depletion in the lamprey, a cyclostome, which diverged from the main vertebrate line around 560 million years ago. The lamprey striatum contains the same cellular elements as found in mammals, and receives the same types of input, including a prominent dopamine innervation. We show here that MPTP (1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine; 100 mg/kg i.p.), a neurotoxin, depletes forebrain and striatal dopamine levels in lamprey to 15% of control values, and has profound effects on motor performance. Twenty‐four and 48 h after MPTP injection, lampreys demonstrated marked reductions in spontaneous swimming and the duration of each swimming episode. Impairments in the ability to initiate movements were shown by a decreased rate of initiation. Furthermore, the initiation and maintenance of locomotion induced by olfactory mucosa stimulation was severely impaired, as was the coordination of different motor tasks. These deficits were ameliorated by the dopamine agonist apomorphine. The motor deficits arising after striatal dopamine depletion are thus qualitatively similar in cyclostomes and mammals. The role of the dopamine innervation of the striatum thus appears to be conserved throughout vertebrate evolution.
Abundance and composition of ammonia‐oxidizing bacteria and ammonia‐oxidizing archaea communities of an alkaline sandy loam
Authors: Shen Ju‐pei , Zhang Li‐mei , Zhu Yong‐guan , Zhang Jia‐bao , He Ji‐zheng
Published: March 2008

The abundance and composition of soil ammonia‐oxidizing bacteria (AOB) and ammonia‐oxidizing archaea (AOA) communities under different long‐term (17 years) fertilization practices were investigated using real‐time polymerase chain reaction and denaturing gradient gel electrophoresis (DGGE). A sandy loam with pH (H2O) ranging from 8.3 to 8.7 was sampled in years 2006 and 2007, including seven fertilization treatments of control without fertilizers (CK), those with combinations of fertilizer nitrogen (N), phosphorus (P) and potassium (K): NP, NK, PK and NPK, half chemical fertilizers NPK plus half organic manure (1/2OMN) and organic manure (OM). The highest bacterial amoA gene copy numbers were found in those treatments receiving N fertilizer. The archaeal amoA gene copy numbers ranging from 1.54 × 107 to 4.25 × 107 per gram of dry soil were significantly higher than those of bacterial amoA genes, ranging from 1.24 × 105 to 2.79 × 106 per gram of dry soil, which indicated a potential role of AOA in nitrification. Ammonia‐oxidizing bacteria abundance had significant correlations with soil pH and potential nitrification rates. Denaturing gradient gel electrophoresis patterns revealed that the fertilization resulted in an obvious change of the AOB community, while no significant change of the AOA community was observed among different treatments. Phylogenetic analysis showed a dominance of Nitrosospira‐like sequences, while three bands were affiliated with the Nitrosomonas genus. All AOA sequences fell within cluster S (soil origin) and cluster M (marine and sediment origin). These results suggest that long‐term fertilization had a significant impact on AOB abundance and composition, while minimal on AOA in the alkaline soil.
Changes in muscle, fat and bone mass after 36 weeks of maximal androgen blockade for prostate cancer
Authors: Galvão Daniel A. , Spry Nigel A. , Taaffe Dennis R. , Newton Robert U. , Stanley John , Shannon Tom , Rowling Chris , Prince Richard
Published: March 2008

OBJECTIVE

To assess the effects of androgen deprivation therapy (ADT) on whole‐body and regional muscle, fat and bone mass in men with prostate cancer without metastatic bone disease.

PATIENTS AND METHODS

Seventy‐two men aged 44–88 years underwent spine, hip and whole‐body dual‐energy X‐ray absorptiometry scans at baseline and after 36 weeks of ADT. The change in whole‐body and regional lean mass (LM), fat mass (FM), and bone mineral content and density (BMD) were determined. In addition, the prostate specific antigen (PSA), serum testosterone and haemoglobin levels were measured, and the level of physical activity and fatigue assessed using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire‐30.

RESULTS

The upper limb, lower limb, trunk and whole‐body LM decreased by a mean (sem) of 5.6 (0.6)%, 3.7 (0.5)%, 1.4 (0.5)% and 2.4 (0.4)% (P < 0.01), respectively, while FM increased by 20.7 (3.3)%, 18.7 (2.7)%, 12.0 (2.5)% and 13.8 (2.3)% (P < 0.001). Hip, spine, whole‐body and upper limb BMD decreased by 1.5 (0.5)%, 3.9 (0.4)%, 2.4 (0.3)% and 1.3 (0.3%) (P < 0.001), but not lower limb BMD. Serum testosterone, PSA and haemoglobin levels decreased by 93.3 (0.4)%, 98.2 (0.5)%, and 8.8 (0.9)% (P < 0.001), respectively. In addition, physical activity levels decreased and levels of fatigue increased.

CONCLUSION

After 36 weeks of ADT there was a significant decrease in whole‐body and regional LM and bone mass, while whole‐body and regional FM increased in older men with prostate cancer. Strategies to counteract changes in soft tissue and bone mass during ADT should be formulated to minimize the risk of sarcopenia, osteoporosis and obesity.
Microsatellite analysis of allelic imbalance in tumour and blood from patients with prostate cancer
Authors: Schwarzenbach Heidi , Chun Felix K.‐H. , Müller Imke , Seidel Christoph , Urban Karoline , Erbersdobler Andreas , Huland Hartwig , Pantel Klaus , Friedrich Martin G.
Published: March 2008

OBJECTIVE

To investigate whether a high frequency of allelic imbalance (AI) is associated with clinicopathological variables of patients with prostate cancer.

PATIENTS AND METHODS

We analysed loss of heterozygosity (LOH) and microsatellite (MS) instability (MSI) on circulating plasma DNA in a polymerase chain reaction (PCR)‐based MS study of 230 patients with prostate cancer and 43 with benign prostatic hyperplasia (BPH) using a panel of 13 polymorphic MS markers.

RESULTS

The overall incidence of AI was significantly higher in primary tumours (34%) than in blood plasma samples from patients with prostate cancer (11%). Although LOH (2.0%) and MSI (1.5%) were also found in BPH plasma samples, their frequencies were low. AI identified in plasma samples from patients with prostate cancer could be retrieved in 63% of the paired tumour samples. The highest concordance of AI and retention of heterozygosity between tumour and plasma samples was 83% at the marker D8S360. There were high frequencies of LOH at the markers THRB, D7S522 and D8S137 in both types of specimens. The markers D11S898 and D11S1313 on the chromosome arm 11q showed frequent MSI. The comparison with established risk factors showed significant associations of an increase in prostate volume with AI at the combined markers D6S474/D7S522 in tumour tissues and at D7S522 in plasma samples (P < 0.04). In the primary tumours there was a further correlation of LOH at D11S1313 with increasing tPSA value (P = 0.005). The combination of total prostate‐specific antigen (PSA) and % free PSA was associated with LOH at THRB in plasma samples.

CONCLUSIONS

Plasma‐based MS analysis may have clinical value for the molecular staging of prostate cancer.
Hypermethylation of the thrombospondin‐1 gene is associated with poor prognosis in penile squamous cell carcinoma
Authors: Guerrero David , Guarch Rosa , Ojer Amaya , Casas Juan Manuel , Ropero Santiago , Mancha Ana , Pesce Carlo , Lloveras Belen , Garcia‐Bragado Federico , Puras Ana
Published: March 2008

OBJECTIVE

To evaluate the presence of human papillomavirus (HPV) infection, the methylation status in the promoter region of thrombospondin‐1 (TSP‐1), RAS association domain family 1A (RASSF1‐A) and p16 genes, and the expression of TSP‐1, CD31, p16 and p53 proteins in patients diagnosed with penile cancer, and the possible associations between these variables and clinical and pathological features.

PATIENTS AND METHODS

HPV types, gene promoter hypermethylation and protein expression were analysed by reverse line blot, methylation‐specific polymerase chain reaction, and immunohistochemistry, respectively, in 24 penile squamous cell carcinomas.

RESULTS

HPV infection was detected in 11 of 24 cases (46%), and TSP‐1, RASSF1‐A and p16 genes were hypermethylated in 46%, 42% and 38% of the tumours, respectively. TSP‐1 hypermethylation was associated with unfavourable histological grade (grade 3; P = 0.033), vascular invasion (P = 0.023), weak expression of TSP‐1 protein (P = 0.041), and shorter overall survival (P = 0.04). TSP‐1 expression was not associated with microvessel density. However, RASSF1‐A hypermethylation was more frequent in T1 tumours (P = 0.01), and p16 hypermethylation was not associated with any of the tested variables except for absence of p16 expression (P = 0.022).

CONCLUSION

In summary, the epigenetic inactivation of TSP‐1 and RASSF1‐A genes is associated with pathological variables and seems to be of prognostic significance in penile cancer.
Clusterin knockdown using the antisense oligonucleotide OGX‐011 re‐sensitizes docetaxel‐refractory prostate cancer PC‐3 cells to chemotherapy
Authors: Sowery Richard D. , Hadaschik Boris A. , So Alan I. , Zoubeidi Amina , Fazli Ladan , Hurtado‐Coll Antonio , Gleave Martin E.
Published: March 2008

OBJECTIVES

To characterize changes in secretory clusterin (sCLU) expression in prostate cancer cells after treatment with docetaxel and to determine whether sCLU knockdown can re‐introduce chemosensitivity in a docetaxel‐resistant, androgen‐independent human prostate cancer model.

PATIENTS AND METHODS

A tissue microarray was constructed for 84 radical prostatectomy (RP) specimens from a multicentre Phase II trial of neoadjuvant combined androgen ablation and docetaxel (CUOG‐P01a) and assessed for changes in the expression of the cytoprotective chaperone sCLU. The human prostate cancer cell line PC‐3 was repeatedly exposed to docetaxel chemotherapyin vitro, and a docetaxel‐resistant cell subline (PC‐3dR) was developed and analysed.

RESULTS

sCLU levels were significantly higher in RP specimens treated with neoadjuvant combined androgen ablation and docetaxel than in untreated specimens. Similarly, sCLU expression increased 2.5‐fold in the newly developed docetaxel‐refractory PC‐3dR cell line compared with parental PC‐3 cells. There was a dose‐dependent and sequence‐specific decrease in sCLU levels in PC‐3dR cells using OGX‐011, an antisense oligonucleotide against human sCLU. OGX‐011 and small‐interference RNA both chemosensitized PC‐3dR cells to docetaxel and mitoxantronein vitroand apoptotic rates in PC‐3dR cells were significantly increased when OGX‐011 was combined with docetaxel.In vivo,growth of PC‐3dR xenografts in nude mice was synergistically inhibited by OGX‐011 combined with paclitaxel or mitoxantrone (by 76% and 44% compared with their mismatch controls, respectively).

CONCLUSION

The present findings indicate that targeted knockdown of sCLU enhances the effects of cytotoxic chemotherapy in docetaxel‐refractory cells, and provide preclinical proof of principle for clinical trials testing OGX‐011 in second‐line chemotherapy regimens for patients with docetaxel‐refractory prostate cancer.
SOCIAL SECURITY AND RETIREMENT DECISION: A POSITIVE AND NORMATIVE APPROACH*
Authors: Cremer Helmuth , Lozachmeur Jean‐Marie , Pestieau Pierre
Published: March 2008

Abstract Social insurance for the elderly is judged responsible for the widely observed trend towards early retirement. In a world of laissez‐faire or in a first‐best setting, there would be no such trend. However, when first‐best instruments are not available, because health and productivity are not observable, the optimal social insurance policy may imply a distortion on the retirement decision. The main point we make is that while there is no doubt that retirement systems induce an excessive bias towards early retirement in many countries, a complete elimination of this bias (i.e. a switch to an actuarially fair system) is not the right answer for two reasons. First, some distortions are second‐best optimal. This is the normative argument. Second, and on the positive side, the elimination of the bias might be problematic from a political perspective. Depending on the political process, either it may not be feasible or alternatively it may tend to undermine the political support for the pension system itself.
Confronting complexity: insights from the details of behavior over multiple timescales
Authors: Samuelson Larissa K. , Horst Jessica S.
Published: March 2008

Young children tend to generalize novel names for novel solid objects by similarity in shape, a phenomenon dubbed ‘the shape bias’. We believe that the critical insights needed to explain the shape bias in particular, and cognitive development more generally, come from Dynamic Systems Theory. We present two examples of recent work focusing on the real‐time decision processes that underlie performance in the tasks used to measure the shape bias. We show how this work, and the dynamic systems perspective, sheds light on the controversy over the origins and development of the shape bias. In addition, we suggest that this dynamic systems perspective provides the right level for explanations of development because it requires a focus on the details of behavior over multiple timescales.
Young children's spontaneous use of geometry in maps
Authors: Shusterman Anna , Ah Lee Sang , Spelke Elizabeth S.
Published: March 2008

Two experiments tested whether 4‐year‐old children extract and use geometric information in simple maps without task instruction or feedback. Children saw maps depicting an arrangement of three containers and were asked to place an object into a container designated on the map. In Experiment 1, one of the three locations on the map and the array was distinct and therefore served as a landmark; in Experiment 2, only angle, distance and sense information specified the target container. Children in both experiments used information for distance and angle, but not sense, showing signature error patterns found in adults. Children thus show early, spontaneously developing abilities to detect geometric correspondences between three‐dimensional layouts and two‐dimensional maps, and they use these correspondences to guide navigation. These findings begin to chart the nature and limits of the use of core geometry in a uniquely human, symbolic task.
Verbal self‐instructions in task switching: a compensatory tool for action‐control deficits in childhood and old age?
Authors: Kray Jutta , Eber Jutta , Karbach Julia
Published: March 2008

This study examined the influence of verbal self‐instructions on age differences in task switching. Task‐switching ability, measured as the difference between performance in single‐task blocks and in mixed‐task blocks in which participants switch between two tasks (mixing costs), increases during childhood and decreases in old age. To measure the influence of language on task switching, we compared conditions in which participants either (a) named the next task to be performed (i.e. task‐relevant verbalization), (b) verbalized words not related to the task at hand (i.e. task‐irrelevant verbalization), or (c) did not verbalize (control condition). Results indicated that mixing costs were substantially reduced under task‐relevant verbalization and increased under task‐irrelevant verbalization. Moreover, age‐related differences in mixing costs were increased when the use of inner speech was disrupted and were reduced when participants performed task‐relevant verbalization. These findings suggest that verbal self‐instructions are a useful tool for retrieving the next task goal and for reducing action‐control deficits in younger children and older adults.
Functional neuroimaging of speech perception during a pivotal period in language acquisition
Authors: Redcay Elizabeth , Haist Frank , Courchesne Eric
Published: March 2008

A pivotal period in the development of language occurs in the second year of life, when language comprehension undergoes rapid acceleration. However, the brain bases of these advances remain speculative as there is currently no functional magnetic resonance imaging (fMRI) data from healthy, typically developing toddlers at this age. We investigated the neural basis of speech comprehension in this critical age period by measuring fMRI activity during passive speech comprehension in 10 toddlers (mean ± SD; 21 ± 4 mo) and 10 3‐year‐old children (39 ± 3 mo) during natural sleep. During sleep, the children were presented passages of forward and backward speech in 20‐second blocks separated by 20‐second periods of no sound presentation. Toddlers produced significantly greater activation in frontal, occipital, and cerebellar regions than 3‐year‐old children in response to forward speech. Our results suggest that rapid language acquisition during the second year of life may require the utilization of frontal, cerebellar, and occipital regions in addition to classical superior temporal language areas. These findings are consistent with the interactive specialization hypothesis, which proposes that cognitive abilities develop from the interaction of brain regions that include and extend beyond those used in the adult brain.
Ethnic conflict in Papua New Guinea
Authors: Reilly Benjamin
Published: March 2008

Abstract:  On many measures of ethno‐linguistic diversity, Papua New Guinea is the most fragmented society in the world. I argue that the macro‐level political effect of this diversity has been to reduce, rather than increase, the impact of ethnic conflict on the state. Outside the Bougainville conflict, and (to a lesser extent) the recent upsurge of violence in the Southern Highlands, ethnic conflicts in Papua New Guinea have not presented a threat to national government. In contrast to most other ethnically diverse societies, the most consequential impacts of ethnic conflict in Papua New Guinea are at the local level. This paper therefore examines the disparate impacts of local‐ and national‐level forms of ethnic conflict in Papua New Guinea.
A political ecology of violence and territory in West Kalimantan
Authors: Peluso Nancy Lee
Published: March 2008

Abstract:  This paper uses a political ecology perspective to examine relationships between violence and territory in West Kalimantan, focusing on the violent incidents of 1996–1997 and 1967–1968. Besides a regional account, the paper examines some of the ways residents of one village were drawn into and chose to participate in violence. The author concludes that while regional analyses can identify broad patterns, local analyses enable a greater understanding of both variation and the processes by which ethnic categories are constructed through violence.
Resources, representation, and authority in Jharkhand, India
Authors: Stuligross David
Published: March 2008

Abstract: Jharkhand is at the centre of India's struggles to define ‘the environment’ and ‘economically relevant natural resources’. Although cultural labels are applied by leaders who seek influence in these struggles as well as by many of those people who listen, an ethnonational analytic frame does not help answer the questions: How, why and when has the political idea of environment changed in India? When and why has the Jharkhand movement chosen violent tactics? When and why has the Jharkhand statehood movement realised electoral success? Or, why was Jharkhand state formed? To address such questions, a long range historical‐institutional approach is much more fruitful.
Duration of Rent Extraction and the Entry Mode Decision of Multinational Enterprises
Authors: An Galina , Maskus Keith E. , Puttitanun Thitima
Published: March 2008

The prior literature is ambiguous about the effects of stronger intellectual property rights (IPR) on the choice of a multinational firm's mode of entry into foreign markets. However, available indexes of IPR protection exist only at the country level and do not identify interindustry variation in the ability to extract rents through exclusive rights and other factors. The authors introduce this dimension and compute a parameter that reflects the relative length of time that positive profits may be earned in various industries. Estimation results find that strengthening IPR would reduce exporting in all industries in the sample. However, it would raise (reduce) foreign direct investment, relative to licensing, in industries with shorter (longer) rent‐extraction times.
Mothers'andFathers' Use of Internal State Talk with their Young Children
Authors: LaBounty Jennifer , Wellman Henry M. , Olson Sheryl , Lagattuta Kristin , Liu David
Published: March 2008

The present study extends previous results demonstrating a relation between maternal discourse and child social understanding to include paternal discourse. Emotion understanding (EU) and theory of mind (ToM) were considered as two distinctive aspects of social understanding. Participants were 106 children (54 boys and 52 girls) studied at 3.5 and 5 years. Discourse measures came from separate parent–child conversations during a picture‐book task; measures of EU and ToM came from children's performance on social cognition tasks. Differences in parental talk translated into important differences in the influence of each parent on children's social‐cognitive understanding. Mothers' references to emotion and emotion causal explanatory language predicted children's concurrent EU. Fathers' use of causal explanatory language referring to desires and emotions predicted children's concurrent and later ToM. These results highlight important differences between mothers and fathers in their use of internal state language and its impact on children's social‐cognitive understanding.
Cultural Transmission of Tool Use in Young Children: A Diffusion Chain Study
Authors: Flynn Emma , Whiten Andrew
Published: March 2008

Developmental and gender effects in the transmission of information about a tool‐use task were investigated within a ‘diffusion chain’ design. One hundred and twenty‐seven children (65 three‐year‐olds and 62 five‐year‐olds) participated. Eighty children took part in diffusion chains in which consecutive children in chains of five witnessed two attempts on a tool‐use task by the previous child in the chain. Comparisons were made between two experimental conditions in which alternative techniques were seeded and a third no‐model control condition. Children in the diffusion chains conformed to the technique they witnessed, in one experimental condition faithfully transmitting a technique absent in the no‐model condition. Five‐year‐olds displayed more robust transmission than three‐year‐olds, and boys were both more competent and displayed stronger transmission than girls.
ISLAM AND BIOETHICS
Authors: Brockopp Jonathan E.
Published: March 2008

Muslim theologians, jurists, and healthcare workers have been addressing the challenges of modern biotechnology for years. Major textbooks on religion and bioethics cover Islam in one or two articles, offering only a general introduction to these important discussions. The five articles in this issue of the Journal of Religious Ethics, originating from a conference at Pennsylvania State University, are unusual in the specificity of their topics—brain death, feeding tubes, sex selection, spiritual counseling, and organ transplantation—and in their engagement with complex discussions in the Muslim and non‐Muslim worlds. In this essay, I introduce the five articles and consider two larger implications: the changing definition of the human person in light of biotechnological advances and the continuing importance of religious traditions, especially Islam, in legitimizing ethical responses to these advances.
Misunderstandings Between Experimentalists and Observationalists about Causal Inference
Authors: Imai Kosuke , King Gary , Stuart Elizabeth A.
Published: March 2008

We attempt to clarify, and suggest how to avoid, several serious misunderstandings about and fallacies of causal inference. These issues concern some of the most fundamental advantages and disadvantages of each basic research design. Problems include improper use of hypothesis tests for covariate balance between the treated and control groups, and the consequences of using randomization, blocking before randomization and matching after assignment of treatment to achieve covariate balance. Applied researchers in a wide range of scientific disciplines seem to fall prey to one or more of these fallacies and as a result make suboptimal design or analysis choices. To clarify these points, we derive a new four-part decomposition of the key estimation errors in making causal inferences. We then show how this decomposition can help scholars from different experimental and observational research traditions to understand better each other’s inferential problems and attempted solutions.
Haematological changes after switching from stavudine to zidovudine in HIV‐infected children receiving highly active antiretroviral therapy
Authors: Aurpibul L , Puthanakit T , Sirisanthana T , Sirisanthana V
Published: March 2008

Objective

In resource‐limited countries, stavudine (d4T) is commonly used as part of the initial highly active antiretroviral therapy (HAART) regimen. Many patients who subsequently develop lipodystrophy switch from d4T to zidovudine (ZDV), a drug that can be myelotoxic. We aimed to study the spectrum and severity of haematological changes following this substitution.

Methods

This was a retrospective cohort study. The inclusion criteria were as follows: HIV‐infected children were included who (1) were 2–15 years old at the time of HAART initiation, (2) had not been diagnosed as having haematological diseases, (3) had been receiving a first HAART regimen consisting of either nevirapine or efavirenz, together with lamivudine and d4T, for at least 48 weeks and (4) had switched from d4T to ZDV at least 48 weeks previously.

Results

Seventy‐eight children were included in the study. Thirty‐six (46%) were male. The mean age was 10.3 years (standard deviation 3.1 years). The switch had been made a median time of 65 weeks (range 48–97 weeks) previously. There was no significant change in CD4 lymphocyte count or percentage, or HIV RNA level, after the switch. There was a statistically significant decrease in haemoglobin level (12.6 vs.12.1 g/dL; P<0.001), total white blood cell (WBC) count (8088 vs. 6910 cells/μL; P<0.001) and absolute neutrophil count (ANC) (4320 vs. 3448 cells/μL; P<0.001). However, the decreases never reached Division of AIDS grade 3 or 4 severity, and none of the patients had clinical symptoms or signs of anaemia, leukopenia, or neutropenia. No participant had to discontinue ZDV during the 48‐week follow‐up period.

Conclusion

In a paediatric population, statistically significant decreases in haemoglobin level, WBC count and ANC occurred following the substitution of d4T with ZDV, but the magnitudes of the decreases were small and not clinically significant.
Reported sexually transmitted infections in Swedish Internet‐using men and women
Authors: Ross MW , Daneback K , Mansson S‐A , Berglund T , Tikkanen R
Published: March 2008

Although the Internet has become a forum for making sexual contacts, and has been associated with increased sexually transmitted infection (STI) transmission, we have little information of history of STIs in Internet‐based samples. The Internet behaviours that are associated with STI acquisition are poorly understood. We analysed STI histories reported by 904 Swedish men and 931 Swedish women who responded to an Internet‐based survey on sexual behaviour in 2002: 16.6% of men and 22.5% of women reported a lifetime history of STIs, with Chlamydia being the most common for both genders. 3% of men and 5% of women who reported an STI, indicated that they had had more than one. Sources of the STI, where known, were Internet‐acquired partners in only 3% of cases. There were no differences between men and women with or without an STI history regarding the kind of online sexual activities they engaged in, how they found sexual material online, and the reasons they engage in sexual activities. These rates are similar to those reported in a national random study of sexuality in Sweden. Contrary to prior research, these results suggest no relationship between STI and specific Internet characteristics usage patterns. These data suggest that the Internet is not yet a major source of STIs in Swedish men and women. Given these STI histories, the Internet may be a useful medium to include in STI prevention efforts.
Arbitrage Bounds and UK Unit Trust Performance
Authors: Fletcher Jonathan , Ntozi‐Obwale Patricia
Published: March 2008

Abstract:  We use the arbitrage performance bounds of Ahn, Cao and Chretien (2003) to evaluate UK unit trust performance between January 1988 and December 2002. We find that trust performance is sensitive to the admissible stochastic discount factor used for both the average trust and the majority of individual trusts. The investment style, size, load charge, and annual charge of the trust all have an impact on trust performance. We find for some trusts, the Jensen (1968) and Ferson and Schadt (1996) measures do not satisfy arbitrage bounds by the base assets.
Traumatic events and suicide‐related outcomes among Mexico City adolescents
Authors: Borges Guilherme , Benjet Corina , Medina‐Mora Maria Elena , Orozco Ricardo , Molnar Beth E. , Nock Matthew K.
Published: March 2008

Background:  We report the prevalence and associations between traumatic events and suicidal ideation, suicide plans and suicide attempts among Mexican adolescents.

Methods:  The data are from a representative multistage probability household survey of 3,005 adolescents aged 12 to 17 years residing in the Mexico City Metropolitan Area that was carried out in 2005. We used discrete time survival analyses to model the net impact of retrospectively reported prior occurrence of traumatic events on ideation, plans and attempts, taking into account the onset of psychiatric disorders.

Results:  Prevalence of suicidality was high among respondents with traumatic events, ranging from a 43% prevalence of suicidal ideation among those with a history of ‘Being raped’ to a 25% prevalence of suicide attempts among those that reported ‘Purposely injured, tortured or killed someone.’ In cross‐sectional estimates, any traumatic event was associated with an increase of 3.2 times the odds of suicide ideation, 5.1 times the odds of a plan and 6.6 times the odds of an attempt. Number of events was also associated with increasing suicidality such that those with three or more events were 13.7 times more likely to report a suicide attempt than those with none. Multivariate discrete time survival models that took into account a large number of demographic, suicide‐related and psychiatric disorder variables reduced in strength but did not alter these basic relationships.

Conclusions:  We conclude that traumatic events such as rape and sexual assault have a profound impact upon suicidality and that this relationship is not entirely explained by the onset of psychiatric disorders. Comprehensive interventions for adolescent victims of traumatic events, especially those with a history of cumulative events, should include, but not be restricted to, treatment of any associated psychiatric disorder.