bluuebunny/crossref_metadata_2025 huggingface dataset:
Working memory task performance and chunking in early
Alzheimer's disease
Authors: Huntley Jonathan , Bor Daniel , Hampshire Adam , Owen Adrian , Howard Robert
Published: April 2011

Background

Chunking is a powerful encoding strategy that significantly improves
working memory performance in normal young people.

Aims

To investigate chunking in patients with mild Alzheimer's disease and in
a control group of elderly people without cognitive impairment.

Method

People with mild Alzheimer's disease (n = 28) were
recruited and divided according to Mini-Mental State Examination score
into mild and very mild disease groups. A control group of 15 elderly
individuals was also recruited. All participants performed digit and
spatial working memory tasks requiring either unstructured sequences or
structured sequences (which encourage chunking of information) to be
recalled.

Results

The control group and both disease groups performed significantly better
on structured trials of the digit working memory tasks, indicating
successful use of chunking strategies to improve verbal working memory
performance. The control and very mild disease groups also performed
significantly better on structured trials of the spatial task, whereas
those with mild disease demonstrated no significant difference between
the structured and unstructured spatial conditions.

Conclusions

The ability to use chunking as an encoding strategy to improve verbal
working memory performance is preserved at the mild stage of Alzheimer's
disease, whereas use of chunking to improve spatial working memory is
impaired by this stage. Simple training in the use of chunking might be a
beneficial therapeutic strategy to prolong working memory functioning in
patients at the earliest stage of Alzheimer's disease.
Keeping therapies simple: psychoeducation in the prevention of
relapse in affective disorders
Authors: Colom Francesc
Published: April 2011

Psychological interventions for mood disorders can be divided into ‘skilled’
and ‘simple‘. Psychoeducation belongs to the latter group: a simple and
illness-focused therapy with prophylactic efficacy in all major mood
disorders. Successful implementation of psychoeducation requires a proper
setting, including open-door policy, team effort and empowerment of the
therapeutic alliance.
Prognostic Significance of Mitotic Rate in Localized Primary Cutaneous Melanoma: An Analysis of Patients in the Multi-Institutional American Joint Committee on Cancer Melanoma Staging Database
Authors: Thompson John F. , Soong Seng-Jaw , Balch Charles M. , Gershenwald Jeffrey E. , Ding Shouluan , Coit Daniel G. , Flaherty Keith T. , Gimotty Phyllis A. , Johnson Timothy , Johnson Marcella M. , Leong Stanley P. , Ross Merrick I. , Byrd David R. , Cascinelli Natale , Cochran Alistair J. , Eggermont Alexander M. , McMasters Kelly M. , Mihm Martin C. , Morton Donald L. , Sondak Vernon K.
Published: April 2011

Purpose

The aim of this study was to assess the independent prognostic value of primary tumor mitotic rate compared with other clinical and pathologic features of stages I and II melanoma.

Methods

From the American Joint Committee on Cancer (AJCC) melanoma staging database, information was extracted for 13,296 patients with stages I and II disease who had mitotic rate data available.

Results

Survival times declined as mitotic rate increased. Ten-year survival ranged from 93% for patients whose tumors had 0 mitosis/mm2 to 48% for those with ≥ 20/mm2 (P < .001). Mean number of mitoses/mm2 increased as the primary melanomas became thicker (1.0 for melanomas ≤ 1 mm, 3.5 for 1.01 to 2.0 mm, 7.3 for 3.01 to 4.0 mm, and 9.6 for > 8 mm). Ulceration was also associated with a higher mitotic rate; 59% of ulcerated melanomas had ≥ 5 mitoses/mm2 compared with 16% of nonulcerated melanomas (P < .001). In a multivariate analysis of 10,233 patients, the independent predictive factors for survival in order of statistical significance were as follows: tumor thickness (χ2 = 104.9; P < .001), mitotic rate (χ2 = 67.0; P < .001), patient age (χ2 = 48.2; P < .001), ulceration (χ2 = 46.4; P < .001), anatomic site (χ2 = 34.6; P < .001), and patient sex (χ2 = 33.9; P < .001). Clark level of invasion was not an independent predictor of survival (χ2 = 3.2; P = .37).

Conclusion

A high mitotic rate in a primary melanoma is associated with a lower survival probability. Among the independent predictors of melanoma-specific survival, mitotic rate was the strongest prognostic factor after tumor thickness.
TP53 Mutations in Low-Risk Myelodysplastic Syndromes With del(5q) Predict Disease Progression
Authors: Jädersten Martin , Saft Leonie , Smith Alexander , Kulasekararaj Austin , Pomplun Sabine , Göhring Gudrun , Hedlund Anette , Hast Robert , Schlegelberger Brigitte , Porwit Anna , Hellström-Lindberg Eva , Mufti Ghulam J.
Published: April 2011

Purpose

To determine the frequency of TP53 mutations and the level of p53 protein expression by immunohistochemistry (IHC) in low-risk myelodysplastic syndromes (MDS) with del(5q) and to assess their impact on disease progression.

Patients and Methods

Pre- and postprogression bone marrow (BM) samples from 55 consecutive patients with International Prognostic Scoring System low risk (n = 32) or intermediate-1 risk (n = 23) were studied by next-generation sequencing of TP53. IHC for p53 was performed on 148 sequential BM samples.

Results

TP53 mutations with a median clone size of 11% (range, 1% to 54%) were detected in 10 patients (18%) already at an early phase of the disease. Mutations were equally common in low-risk and intermediate-1–risk patients and were associated with evolution to acute myeloid leukemia (5 of 10 v 7 of 45; P = .045). Nine of 10 patients carrying mutations showed more than 2% BM progenitors with strong p53 staining. The probability of a complete cytogenetic response to lenalidomide was lower in mutated patients (0 of 7 v 12 of 24; P = .024).

Conclusion

By using sensitive deep-sequencing technology, we demonstrated that TP53 mutated populations may occur at an early disease stage in almost a fifth of low-risk MDS patients with del(5q). Importantly, mutations were present years before disease progression and were associated with an increased risk of leukemic evolution. TP53 mutations could not be predicted by common clinical features but were associated with p53 overexpression. Our findings indicate a previously unrecognized heterogeneity of the disease which may significantly affect clinical decision making.
Primary Health and Supportive Care Needs of Long-Term Cancer Survivors: A Questionnaire Survey
Authors: Harrison Siân E. , Watson Eila K. , Ward Alison M. , Khan Nada F. , Turner Daniel , Adams Eike , Forman David , Roche Monica F. , Rose Peter W.
Published: April 2011

Purpose

There are 1.2 million long-term cancer survivors in the United Kingdom. Existing research on the health and supportive care needs of these survivors is sparse and inconclusive. This study investigated health status, psychological morbidity, and supportive care needs in long-term cancer survivors in the United Kingdom.

Methods

Five to 16 years after diagnosis, 1,275 eligible survivors of breast, colorectal, and prostate cancers were approached to participate in a questionnaire survey. The questionnaire explored health status (European Quality of Life–5 Dimensions), psychological morbidity (Hospital Anxiety and Depression Scale), and supportive care needs (Cancer Survivors' Unmet Needs Measure). Data were analyzed by type of cancer and time since diagnosis. Logistic regression was used to identify predictors of unmet supportive care needs.

Results

The response rate was 51.7% (659 survivors). Overall health status and levels of psychological morbidity were consistent with population norms. At least one unmet supportive care need was reported by 47.4% of survivors, but overall numbers of unmet needs were low (mean, 2.8; standard deviation, 4.8). The most frequently endorsed unmet need was for help to manage concerns about cancer recurrence. Trait anxiety (P < .001), nondischarged status (P < .01), dissatisfaction with discharge (P < .01), and receipt of hormonal therapy (P < .01) were predictive of unmet supportive care needs.

Conclusion

The findings suggest a majority of long-term breast, colorectal, and prostate cancer survivors who have no signs of recurrence report good health and do not have psychological morbidity or large numbers of unmet supportive care needs. A minority of long-term survivors may benefit from ongoing support. The identification and support of those long-term survivors with ongoing needs is a key challenge for health care professionals.
Nephric duct insertion is a crucial step in urinary tract maturation that is regulated by aGata3-Raldh2-Retmolecular network in mice
Authors: Chia Ian , Grote David , Marcotte Michael , Batourina Ekaterina , Mendelsohn Cathy , Bouchard Maxime
Published: April 2011

Urinary tract development depends on a complex series of events in which the ureter moves from its initial branch point on the nephric duct (ND) to its final insertion site in the cloaca (the primitive bladder and urethra). Defects in this maturation process can result in malpositioned ureters and hydronephrosis, a common cause of renal disease in children. Here, we report that insertion of the ND into the cloaca is an unrecognized but crucial step that is required for proper positioning of the ureter and that depends on Ret signaling. Analysis of Ret mutant mice at birth reveals hydronephrosis and defective ureter maturation, abnormalities that our results suggest are caused, at least in part, by delayed insertion of the ND. We find a similar set of malformations in mutants lacking either Gata3 or Raldh2. We show that these factors act in parallel to regulate ND insertion via Ret. Morphological analysis of ND extension in wild-type embryos reveals elaborate cellular protrusions at ND tips that are not detected in Ret, Gata3 or Raldh2 mutant embryos, suggesting that these protrusions may normally be important for fusion with the cloaca. Together, our studies reveal a novel Ret-dependent event, ND insertion, that, when abnormal, can cause obstruction and hydronephrosis at birth; whether ND defects underlie similar types of urinary tract abnormalities in humans is an interesting possibility.
The nucleoporin Seh1 forms a complex with Mio and serves an essential tissue-specific function in Drosophila oogenesis
Authors: Senger Stefania , Csokmay John , Akbar Tanveer , Jones Takako Iida , Sengupta Prabuddha , Lilly Mary A.
Published: April 2011

The nuclear pore complex (NPC) mediates the transport of macromolecules between the nucleus and cytoplasm. Recent evidence indicates that structural nucleoporins, the building blocks of the NPC, have a variety of unanticipated cellular functions. Here, we report an unexpected tissue-specific requirement for the structural nucleoporin Seh1 during Drosophila oogenesis. Seh1 is a component of the Nup107-160 complex, the major structural subcomplex of the NPC. We demonstrate that Seh1 associates with the product of the missing oocyte (mio) gene. In Drosophila, mio regulates nuclear architecture and meiotic progression in early ovarian cysts. Like mio, seh1 has a crucial germline function during oogenesis. In both mio and seh1 mutant ovaries, a fraction of oocytes fail to maintain the meiotic cycle and develop as pseudo-nurse cells. Moreover, the accumulation of Mio protein is greatly diminished in the seh1 mutant background. Surprisingly, our characterization of a seh1 null allele indicates that, although required in the female germline, seh1 is dispensable for the development of somatic tissues. Our work represents the first examination of seh1 function within the context of a multicellular organism. In summary, our studies demonstrate that Mio is a novel interacting partner of the conserved nucleoporin Seh1 and add to the growing body of evidence that structural nucleoporins can have novel tissue-specific roles.
Effects of oxygen availability on maximum aerobic performance inMus musculusselected for basal metabolic rate or aerobic capacity
Authors: Gębczyński Andrzej K. , Konarzewski Marek
Published: April 2011

Maximum aerobic metabolism cannot increase indefinitely in response to demands for ATP production and, therefore, must be constrained by one (or many) of the steps of the oxygen transport and utilization pathways. To elucidate those constraints we compared peak metabolic rate elicited by running () in hypoxia (14% O2), normoxia (21% O2) and hyperoxia (30% O2) of laboratory mice divergently selected for low and high basal metabolic rate (L-BMR and H-BMR, respectively), mice selected for maximum metabolic rate elicited by swimming () and mice from unselected lines. In all line types was lowest in hypoxia, intermediate in normoxia and highest in hyperoxia, which suggests a ‘central’ limitation of oxygen uptake or delivery instead of a limit set by cellular oxidative capacity. However, the existence of a common central limitation is not in agreement with our earlier studies showing that selection on high (in contrast to selection on high BMR) resulted in considerably higher oxygen consumption during cold exposure in a He–O2 atmosphere than . Likewise, between-line-type differences in heart mass and blood parameters are inconsistent with the notion of central limitation. Although responses of to hypoxia were similar across different selection regimens, the selection lines showed contrasting responses under hyperoxic conditions. in the H-BMR line type was highest, suggesting that selection on high BMR led to increased cellular oxidative capacity. Overall, between-line-type differences in the effect of the oxygen partial pressure on and in the components of O2 flux pathways are incompatible with the notion of symmorphosis. Our results suggest that constraints on are context dependent and determined by interactions between the central and peripheral organs and tissues involved in O2 delivery.
Adiponectin reduces proteinuria in streptozotocin-induced diabetic Wistar rats
Authors: Nakamaki Shintaro , Satoh Hiroaki , Kudoh Akihiro , Hayashi Yoshimitsu , Hirai Hiroyuki , Watanabe Tsuyoshi
Published: April 2011

The aim of the paper is to investigate the effects of adiponectin in diabetic nephropathy; we used an adenovirus to over-express adiponectin (Ad-Adipo) in streptozotocin (STZ)-induced diabetic rats. Animals were injected with either Ad-Adipo or control Ad-lacZ at 10 weeks after STZ treatment, and at two weeks postadenovirus injection, renal function was assessed. The degree of proteinuria was significantly reduced in Ad-Adipo rats compared with Ad-lacZ rats. Consistent with this, the mRNA expression levels of nephrin and transforming growth factor β (TGF- β) were significantly increased and decreased in the renal cortex of Ad-Adipo rats, respectively. Moreover, adiponectin over-expression in STZ rats decreased markers of endothelial dysfunction, a feature of diabetic nephropathy disease progression. Endothelin 1 (ET-1), plasminogen activator inhibitor 1 (PAI-1) and inducible nitric oxide synthase (iNOS) mRNA expression levels were significantly reduced in the renal cortex of Ad-Adipo rats, respectively. Concurrently, mRNA expression levels of endothelial nitric oxide synthase (eNOS), a positive regulator of endothelial function, were significantly increased in the renal cortex of Ad-Adipo rats. We have shown that chronic hyperadiponectinemia significantly alleviated the progression of proteinuria in early stage diabetic nephropathy. The mechanism whereby adiponectin decreases proteinuria involves an increase in nephrin expression, and an improvement of the endothelial dysfunction due to decreases in ET-1 and PAI-1, and an increase in eNOS expression in the renal cortex. Thus, over-expression of adiponectin has beneficial effects on early stage diabetic nephropathy.
Plant siRNAs from introns mediate DNA methylation of host genes
Authors: Chen Dijun , Meng Yijun , Yuan Chunhui , Bai Lin , Huang Donglin , Lv Shaolei , Wu Ping , Chen Ling-ling , Chen Ming
Published: April 2011

Small RNAs (sRNAs), largely known as microRNAs (miRNAs) and short interfering RNAs (siRNAs), emerged as the critical components of genetic and epigenetic regulation in eukaryotic genomes. In animals, a sizable portion of miRNAs reside within the introns of protein-coding genes, designated as mirtron genes. Recently, high-throughput sequencing (HTS) revealed a huge amount of sRNAs that derived from introns in plants, such as the monocot rice (Oryza sativa). However, the biogenesis and the biological functions of this kind of sRNAs remain elusive. Here, we performed a genome-scale survey of intron-derived sRNAs in rice based on HTS data. Several introns were found to have great potential to form internal hairpin structures, and the short hairpins could generate miRNAs while the larger ones could produce siRNAs. Furthermore, 22 introns, termed “sirtrons,” were identified from the rice protein-coding genes. The single-stranded sirtrons produced a diverse set of siRNAs from long hairpin structures. These sirtron-derived siRNAs are dominantly 21 nt, 22 nt, and 24 nt in length, whose production relied on DCL4, DCL2, and DCL3, respectively. We also observed a strong tendency for the sirtron-derived siRNAs to be coexpressed with their host genes. Finally, the 24-nt siRNAs incorporated with Argonaute 4 (AGO4) could direct DNA methylation on their host genes. In this regard, homeostatic self-regulation between intron-derived siRNAs and their host genes was proposed.
A domain of the actin binding protein Abp140 is the yeast methyltransferase responsible for 3-methylcytidine modification in the tRNA anti-codon loop
Authors: D'Silva Sonia , Haider Steffen J. , Phizicky Eric M.
Published: April 2011

The 3-methylcytidine (m3C) modification is widely found in eukaryotic species of tRNASer, tRNAThr, and tRNAArg; at residue 32 in the anti-codon loop; and at residue e2 in the variable stem of tRNASer. Little is known about the function of this modification or about the specificity of the corresponding methyltransferase, since the gene has not been identified. We have used a primer extension assay to screen a battery of methyltransferase candidate knockout strains in the yeast Saccharomyces cerevisiae, and find that tRNAThr(IGU) from abp140-Δ strains lacks m3C. Curiously, Abp140p is composed of a poorly conserved N-terminal ORF fused by a programed +1 frameshift in budding yeasts to a C-terminal ORF containing an S-adenosylmethionine (SAM) domain that is highly conserved among eukaryotes. We show that ABP140 is required for m3C modification of substrate tRNAs, since primer extension is similarly affected for all tRNA species expected to have m3C and since quantitative analysis shows explicitly that tRNAThr(IGU) from an abp140-Δ strain lacks m3C. We also show that Abp140p (now named Trm140p) purified after expression in yeast or Escherichia coli has m3C methyltransferase activity, which is specific for tRNAThr(IGU) and not tRNAPhe and occurs specifically at C32. We suggest that the C-terminal ORF of Trm140p is necessary and sufficient for activity in vivo and in vitro, based on analysis of constructs deleted for most or all of the N-terminal ORF. We also suggest that m3C has a role in translation, since trm140-Δ trm1-Δ strains (also lacking m2,2G26) are sensitive to low concentrations of cycloheximide.
Actin-binding protein ABP140 is a methyltransferase for 3-methylcytidine at position 32 of tRNAs in Saccharomyces cerevisiae
Authors: Noma Akiko , Yi Sanghyun , Katoh Takayuki , Takai Yoshimi , Suzuki Takeo , Suzuki Tsutomu
Published: April 2011

Transfer RNAs contain various modified nucleotides that are introduced enzymatically at the post-transcriptional level. In Saccharomyces cerevisiae, 3-methylcytidine (m3C) is found at position 32 of the tRNAs for Thr and Ser. We used a systematic reverse genetic approach combined with mass spectrometry (ribonucleome analysis), and identified the actin-binding protein ABP140 as the protein responsible for m3C formation in both tRNAThr1 and tRNASer1. ABP140 consists of an N-terminal actin-binding sequence and a C-terminal S-adenosylmethionine (Ado-Met) binding motif. Deletion of the actin-binding sequence in ABP140 did not affect m3C formation, indicating that subcellular localization of ABP140 to actin filaments is not involved in tRNA modification. m3C formation in tRNAThr1 could be reconstituted using recombinant Abp140p in the presence of Ado-Met, whereas m3C did not form in tRNASer1 in vitro, indicating the absence of a factor(s) required for tRNASer1 m3C formation. Thus, ABP140 has been designated TRM140 according to the preferred nomenclature. In addition, we observed a specific reduction of m3C formation in HeLa cells by siRNA-mediated knock down of the human ortholog of TRM140.
Optimal Detection of Fetal Chromosomal Abnormalities by Massively Parallel DNA Sequencing of Cell-Free Fetal DNA from Maternal Blood
Authors: Sehnert Amy J , Rhees Brian , Comstock David , de Feo Eileen , Heilek Gabrielle , Burke John , Rava Richard P
Published: April 2011

BACKGROUND

Massively parallel DNA sequencing of cell-free fetal DNA from maternal blood can detect fetal chromosomal abnormalities. Although existing algorithms focus on the detection of fetal trisomy 21 (T21), these same algorithms have difficulty detecting trisomy 18 (T18).

METHODS

Blood samples were collected from 1014 patients at 13 US clinic locations before they underwent an invasive prenatal procedure. All samples were processed to plasma, and the DNA extracted from 119 samples underwent massively parallel DNA sequencing. Fifty-three sequenced samples came from women with an abnormal fetal karyotype. To minimize the intra- and interrun sequencing variation, we developed an optimized algorithm by using normalized chromosome values (NCVs) from the sequencing data on a training set of 71 samples with 26 abnormal karyotypes. The classification process was then evaluated on an independent test set of 48 samples with 27 abnormal karyotypes.

RESULTS

Mapped sites for chromosomes of interest in the sequencing data from the training set were normalized individually by calculating the ratio of the number of sites on the specified chromosome to the number of sites observed on an optimized normalizing chromosome (or chromosome set). Threshold values for trisomy or sex chromosome classification were then established for all chromosomes of interest, and a classification schema was defined. Sequencing of the independent test set led to 100% correct classification of T21 (13 of 13) and T18 (8 of 8) samples. Other chromosomal abnormalities were also identified.

CONCLUSION

Massively parallel sequencing is capable of detecting multiple fetal chromosomal abnormalities from maternal plasma when an optimized algorithm is used.
In Situ Testing of Soft Soil at a Case Study Site with the Self-Boring Pressuremeter
Authors: Arulrajah A. , Bo M. W. , Piratheepan J. , Disfani M. M.
Published: April 2011

The Changi East Reclamation Project in the Republic of Singapore involves improvement of marine clay by means of installation of prefabricated vertical drains and subsequent preloading. The in situ testing site was located in the Northern area of the project where the thickest compressible marine clay layers existed. The in situ testing site comprises of a vertical drain area where vertical drains were installed at 1.5 m square spacing and an adjacent control area without vertical drains. Both areas were preloaded with the same magnitude of preload over and above of proposed finished level. In situ tests were carried out using the self-boring pressuremeter test (SBPT) to determine especially the undrained shear strength and overconsolidation ratio of the marine clay together with some other geotechnical parameters prior to reclamation and after 23 month of preloading. In situ dissipation tests were also undertaken with the SBPT to provide a means of evaluating the in situ coefficient of consolidation due to horizontal flow (ch) and horizontal hydraulic conductivity (kh) of Singapore marine clay at Changi. Degree of consolidation was assessed 23 months after preloading using SBPTs data. The SBPT test indicates that the degree of consolidation of the vertical drain area had attained a degree of consolidation of about 80 % while the control area had attained a degree of consolidation of about 20–30 %. The ch determined by the SBPT prior to reclamation is noted to be an order of magnitude greater than the laboratory data. The kh results from SBPT in the Singapore marine clay are in the 10−9 to 10−11 m/s range.
Distinct Visual Pathways MediateDrosophilaLarval Light Avoidance and Circadian Clock Entrainment
Authors: Keene Alex C. , Mazzoni Esteban O. , Zhen Jamie , Younger Meg A. , Yamaguchi Satoko , Blau Justin , Desplan Claude , Sprecher Simon G.
Published: April 2011

Visual organs perceive environmental stimuli required for rapid initiation of behaviors and can also entrain the circadian clock. The larval eye ofDrosophilais capable of both functions. Each eye contains only 12 photoreceptors (PRs), which can be subdivided into two subtypes. Four PRs express blue-sensitiverhodopsin5(rh5) and eight express green-sensitiverhodopsin6(rh6). We found that either PR-subtype is sufficient to entrain the molecular clock by light, while only the Rh5-PR subtype is essential for light avoidance. Acetylcholine released from PRs confers both functions. Both subtypes of larval PRs innervate the main circadian pacemaker neurons of the larva, the neuropeptide PDF (pigment-dispersing factor)-expressing lateral neurons (LNs), providing sensory input to control circadian rhythms. However, we show that PDF-expressing LNs are dispensable for light avoidance, and a distinct set of three clock neurons is required. Thus we have identified distinct sensory and central circuitry regulating light avoidance behavior and clock entrainment. Our findings provide insights into the coding of sensory information for distinct behavioral functions and the underlying molecular and neuronal circuitry.
Reduction of an Afterhyperpolarization Current Increases Excitability in Striatal Cholinergic Interneurons in Rat Parkinsonism
Authors: Sanchez Gonzalo , Rodriguez Mariano Julian , Pomata Pablo , Rela Lorena , Murer Mario Gustavo
Published: April 2011

Striatal cholinergic interneurons show tonic spiking activity in the intact and sliced brain, which stems from intrinsic mechanisms. Because of it, they are also known as “tonically active neurons” (TANs). Another hallmark of TAN electrophysiology is a pause response to appetitive and aversive events and to environmental cues that have predicted these events during learning. Notably, the pause response is lost after the degeneration of dopaminergic neurons in animal models of Parkinson's disease. Moreover, Parkinson's disease patients are in a hypercholinergic state and find some clinical benefit in anticholinergic drugs. Current theories propose that excitatory thalamic inputs conveying information about salient sensory stimuli trigger an intrinsic hyperpolarizing response in the striatal cholinergic interneurons. Moreover, it has been postulated that the loss of the pause response in Parkinson's disease is related to a diminution ofIsAHP, a slow outward current that mediates an afterhyperpolarization following a train of action potentials. Here we report thatIsAHPinduces a marked spike-frequency adaptation in adult rat striatal cholinergic interneurons, inducing an abrupt end of firing during sustained excitation. Chronic loss of dopaminergic neurons markedly reducesIsAHPand spike-frequency adaptation in cholinergic interneurons, allowing them to fire continuously and at higher rates during sustained excitation. These findings provide a plausible explanation for the hypercholinergic state in Parkinson's disease. Moreover, a reduction ofIsAHPmay alter synchronization of cholinergic interneurons with afferent inputs, thus contributing to the loss of the pause response in Parkinson's disease.
Praxisorientierte Modellierung von Pumpensystemen für Monitoring, Regelung und Diagnose
Authors: Kleinmann Stefan , Stetter Ralf , Jalal Abdul
Published: April 2011

Der folgende Beitrag beschreibt die Entwicklung eines Modells von Dreispindelpumpen. Solche Pumpen werden heute in vielfältigen Anwendungsgebieten eingesetzt, z. B. in der Energieerzeugung. Das Modell dient der Simulation des Pumpensystems und soll in weiteren Schritten in vereinfachter Form in der Steuerung der Pumpe integriert werden, um fortgeschrittene modellbasierte Verfahren des Monitoring, der Regelung und Diagnose ermöglichen. Die Ergebnisse stammen aus einem gemeinsamen Projekt eines führenden Systemanbieters im Pumpembereich und dreier Hochschulen in Deutschland, Polen und der Schweiz.
Kompensation von harmonischen Störungen in piezoelastischen Strukturen
Authors: Rittenschober Thomas , Schlacher Kurt
Published: April 2011

Die Verwendung von piezoelektrischer Self-Sensing Aktuatorik in smarten Strukturen gestattet die Kollokation von Aktuatorik und Sensorik, vorausgesetzt, es gelingt eine robuste Trennung des elektrischen Stroms infolge des direkten piezoelektrischen Effekts vom gemessenen elektrischen Strom. Aufgrund des nachteiligen Verhältnisses der beiden Signale wird der Entwurf eines approximativen Beobachters für den elektrischen Strom infolge des direkten piezoelektrischen Effekts vorgeschlagen. Der Reglerentwurf basiert auf einer Erweiterung der Strecke durch ein Störgrößenmodell mit dem Ziel der asymptotischen Unterdrückung harmonischer Störungen. Die Stabilitätsuntersuchungen für das verteilt parametrische System basieren auf dem Satz über die kleine Verstärkungen. Die Effizienz des vorgeschlagenen Regelungskonzept wird an Hand einer piezoelastischen Struktur, die mit einer dominanten Eigenfrequenz angeregt wird, sowohl durch Simulation als auch im Laborversuch demonstriert.
Automatische Klassifikation von Bildzeitreihen für toxikologische Hochdurchsatz-Untersuchungen
Authors: Alshut Rüdiger , Mikut Ralf , Legradi Jessica , Liebel Urban , Strähle Uwe , Bretthauer Georg , Reischl Markus
Published: April 2011

Die vorliegende Arbeit stellt eine neue bildbasierte Methode zur automatischen Klassifikation der Spontanbewegung und des Herzschlags in toxikologisch behandelten Zebrabärblingslarven vor, die sich für Hochdurchsatz-Verfahren in der Toxikologie eignet. Dabei werden neue Akquisestrategien vorgeschlagen, Merkmale aus Bildzeitreihen extrahiert und Klassifikatoren entworfen. Diese werden iterativ kombiniert und anhand von drei Substanzen prototypisch experimentell erprobt.
Testgenerierung für die Werkstattdiagnose auf der Basis struktureller Modelle
Authors: Ungermann Michael , Schwarzmann Dieter , Lunze Jan
Published: April 2011

Es wird ein Verfahren zur Bestimmung von automatischen Tests für die Werkstattdiagnose vorgestellt, das ein strukturelles Modell des zu diagnostizierenden Systems nutzt, in dem die Ursache-Wirkungsbeziehungen im fehlerfreien und im fehlerbehafteten Zustand dargestellt sind. Durch die ausgewählten Tests wird das System in Betriebszustände gesteuert, in denen bestimmte Fehler eine signifikante Wirkung entfalten während die Wirkung anderer Fehler verschwindet. Die Vorgehensweise wird am Beispiel der Drosselklappe eines Pkw-Motors illustriert.
Paralleles Rechnen von modellprädiktiven Regelungen auf der Optimierungsebene
Authors: Behrendt Stefan , Dünow Peter , Steinbrecher Christian , Lampe Bernhard P.
Published: April 2011

Der Beitrag beschreibt ein Konzept zur Parallelisierung eines modellprädiktiven Regelungsverfahrens für lineare Prozessmodelle unter Berücksichtigung von Stellbegrenzungen. Durch die Parallelisierung auf der Basis von Mehrkern-Mikrocontrollern wird der Einsatz solcher Regelungen in eingebetteten Steuerungen auch für Prozessumgebungen mit hoher Dynamik erleichtert. Der Geschwindigkeitsgewinn der parallelen Implementierung hängt in hohem Maße von der Wahl geeigneter Startwerte ab. Im Beitrag werden ein heuristischer und ein systematischer Ansatz zur Ermittlung solcher Startwerte untersucht.
Regelung des EXPO-Pendels
Authors: Gorius Thomas , Seifried Robert , Eberhard Peter
Published: April 2011

Der deutsche Pavillon bei der Weltausstellung EXPO 2010 in Shanghai zeigte als seine Hauptattraktion ein großes interaktives Pendel. Das wichtigste Element dieses Pendels ist eine Kugel mit einem Durchmesser von 3 m, die mit ca. 400.000 LEDs bestückt ist. Die Kugel ist mithilfe einer dünnen Stange und einem Kardan-Gelenk an einem Kreuztisch aufgehängt und liefert den Zuschauern eine Licht- und Bewegungsshow. Dabei führt das Pendel sowohl große ebene Schwingungen als auch Kreisbewegungen aus, während die Bewegungen des Kreuztisches harten Beschränkungen unterliegen. In diesem Beitrag werden die hierfür entwickelten Regelungskonzepte vorgestellt und deren Wirksamkeit anhand von Experimenten gezeigt.
Hochempfindliche Dünnschichtsensoren basierend auf Terahertz-Wellenleitern
Authors: Theuer Michael , Grischkowsky Daniel R. , Beigang René
Published: April 2011

Terahertz Zeitbereichs-Spektroskopie ist in der Lage, durch Laufzeitanalyse dünne dielektrische Schichten aufzulösen. Durch die neue Messanordnung eines Zwei-Zylinder Wellenleiters konnte die Empfindlichkeit um den Faktor 150 auf bis zu 2,5 Mikrometer gesteigert werden. Eine Fehlerabschätzung lässt sogar eine sub-Mikrometer Auflösung erwarten. Selbst auf metallischen Folien ist dadurch die Dicke von dünnsten dielektrischen Schichten präzise zu bestimmen.
Zeitaufgelöste 3D3K Geschwindigkeitsfeldmessungen mit der fernmikroskopischen Astigmatismus PTV zur Analyse der elektrochemischen Kupferabscheidung
Authors: Cierpka Christian , Tschulik Kristina , Segura Rodrigo , Uhlemann Margitta , Kähler Christian J.
Published: April 2011

Der Einsatz der fernmikroskopischen 3D Astigmatismus PTV Methode ermöglicht die zeitlich und räumlich hochaufgelöste Messung des kompletten Geschwindigkeitsfeldes in einem Volumen. Die Methode kommt dabei ohne komplexe Kalibrierung mit nur einem optischen Zugang aus und arbeitet sehr zuverlässig. Es gelang hiermit erstmals die sehr komplexe Strömung, welche durch die Überlagerung der Lorentzkraft und der Magnetfeldgradientenkraft bei der elektrochemischen Kupferabscheidung entsteht, experimentell zu analysieren.
Micro Particle-Image-Velocimetry für Gasströmungen in Mikrokanälen
Authors: Burgmann Sebastian , van der Schoot Nadine , Wartmann Jens , Lindken Ralph
Published: April 2011

Es wird ein Messverfahren vorgestellt, mit dem sich die Geschwindigkeitsverteilung einer Mikrokanalströmung in der Gas- oder Flüssigphase bestimmen lässt. Diese Micro Particle-Image-Velocimetry (μPIV) genannte Technik ist ein berührungsloses, laseroptisches Geschwindigkeitsmessverfahren, das auf der Detektion von kleinsten der Strömung zugegebenen Partikeln bzw. deren Verschiebung beruht. Die μPIV ist insbesondere beim Einsatz in Gasströmungen entscheidend von den Partikeleigenschaften wie Fluoreszenz, Partikelgrößenverteilung und Partikelkonzentration abhängig. Das Partikelfolgeverhalten stellt einen kritischen Parameter der μPIV in Gasströmung dar. Die Messtechnik wird hier exemplarisch in einem optisch transparenten Mikrokanal mit einer 90°-Umlenkung angewendet, um die Anwendbarkeit der μPIV sowohl in einer Wasser- als auch einer Gasströmung zu demonstrieren.
Victimization, Aggression, and Visits to the School Nurse for Somatic Complaints, Illnesses, and Physical Injuries
Authors: Vernberg Eric M. , Nelson Timothy D. , Fonagy Peter , Twemlow Stuart W.
Published: April 2011

OBJECTIVE:

To examine how involvement in aggressor-victim interactions is linked to somatic complaints, illnesses, and physical injuries among elementary school–aged children.

STUDY DESIGN:

This study was composed of a school-based sample of 590 children in grades 3 through 5. Independent sources were used to assess victimization (self-report) and aggression (peer report) in the fall semester. School nursing logs for the entire school year were collected in May and coded for the number of times each child presented with a somatic complaint, illness, or injury.

RESULTS:

Both aggression and victimization were significantly related to all 3 reasons for nurse visits, controlling for demographic variables. Higher levels of aggression and victimization each were independently associated with more frequent visits to the school nurse for somatic complaints, illnesses, and injuries. A significant victimization-times-aggression interaction was found for illnesses, with nonaggressive victimized children presenting most frequently for illness visits.

CONCLUSIONS:

Involvement in aggressor-victim interactions, as either aggressor, victim, or both, is associated with more frequent health complaints, based on school nursing logs. Prevention, early identification, and treatment of problems with victimization and aggression may have important health implications for children.
Natural Progression of Neurological Disease in Mucopolysaccharidosis Type II
Authors: Holt Joshua B. , Poe Michele D. , Escolar Maria L.
Published: April 2011

OBJECTIVE:

Mucopolysaccharidosis type II (MPS II) is a lysosomal storage disorder characterized by insufficiency of the iduronate-2-sulfatase enzyme, which results in excess heparan and dermatan sulfates within the lysosomes of various tissues and organs, including the central nervous system. The purpose of this study was to investigate the natural progression of neurologic disease in a large cohort of patients evaluated with standardized testing at a single institution.

METHODS:

During the period of December 2002 to October 2010, patients with MPS II were referred to the Program for Neurodevelopmental Function in Rare Disorders. A retrospective review of patient data was performed, which included the use of detailed questionnaires that addressed medical history, notes from previous health care providers, and the results of a multidisciplinary evaluation that lasted 4 to 6 hours and was performed by a team of neurodevelopmental pediatricians, speech pathologists, psychologists, audiologists, psychometricians, and occupational and physical therapists. Patients were evaluated annually for management of disease progression.

RESULTS:

A total of 50 male patients with MPS II were evaluated over 152 encounters. Two distinct subgroups of children were identified. One subset of patients had normal cognitive, speech and language, and adaptive functions whereas the other showed a dramatic decline in these areas. All patients developed fine and gross motor deficits.

CONCLUSION:

The natural progression of MPS II manifests as 2 divergent and distinct neurologic phenotypes with similar somatic disease. Patients may have primary neural parenchymal disease with cognitive involvement or may maintain normal cognitive abilities.
Early Childhood Stimulation Benefits Adult Competence and Reduces Violent Behavior
Authors: Walker Susan P. , Chang Susan M. , Vera-Hernández Marcos , Grantham-McGregor Sally
Published: April 2011

OBJECTIVE:

An estimated 178 million children younger than 5 years in developing countries experience linear growth retardation and are unlikely to attain their developmental potential. We aimed to evaluate adult benefits from early childhood stimulation and/or nutritional supplementation in growth-retarded children.

METHODS:

In Kingston, Jamaica, 129 growth-retarded children aged 9 to 24 months took part in a 2-year trial of nutritional supplementation (1 kg milk-based formula per week) and/or psychosocial stimulation (weekly play sessions to improve mother-child interaction). We assessed IQ, educational attainment, and behavior at 22 years old in 105 participants. We used multivariate regressions, weighted to adjust for loss to follow-up, to determine treatment benefits.

RESULTS:

We found no significant benefits from supplementation. Participants who received stimulation reported less involvement in fights (odds ratio: 0.36 [95% confidence interval (CI) 0.12–1.06]) and in serious violent behavior (odds ratio: 0.33 [95% CI: 0.11–0.93]) than did participants with no stimulation. They also had higher adult IQ (coefficient: 6.3 [95% CI: 2.2–10.4]), higher educational attainment (achievement, grade level attained, and secondary examinations), better general knowledge, and fewer symptoms of depression and social inhibition.

CONCLUSIONS:

Early psychosocial intervention had wide-ranging benefits in adulthood that are likely to facilitate functioning in everyday life. The reductions in violent behavior are extremely important given the high levels of violence in many developing countries. The study provides critical evidence that early intervention can lead to gains in adult functioning.
Risk-Taking Behaviors of Adolescents With Extreme Obesity: Normative or Not?
Authors: Ratcliff Megan Benoit , Jenkins Todd M. , Reiter-Purtill Jennifer , Noll Jennie G. , Zeller Meg H.
Published: April 2011

OBJECTIVE:

Present first published data detailing high-risk behaviors of adolescent high school students (HSS) with extreme obesity (BMI ≥ 99th percentile for age and gender) compared with healthy weight peers (5th–84th percentile).

METHODS:

The 2007 Youth Risk Behavior Survey was used to compare HSS with extreme obesity (N = 410) and healthy weight peers (N = 8669) in their engagement in (1) tobacco use, (2) alcohol/other drug use, (3) high-risk sexual behaviors, and (4) suicidal behaviors. Logistic regression was used to calculate gender-stratified odds ratios (OR) and 95% confidence intervals (CI), controlling for age and race.

RESULTS:

HSS with extreme obesity were similar to healthy weight peers in the prevalence of most behaviors related to alcohol/drug use, high-risk sexual activities, and suicide, with the following exceptions: relative to healthy weight HSS, both male and female students with extreme obesity more frequently reported ever trying cigarettes (female students, adjusted OR: 2.0 [95% CI: 1.3–3.2]; male students, OR: 1.5 [CI: 1.2–2.0]). Compared with healthy weight female students, female students with extreme obesity had lower odds of ever having sex (OR: 0.5 [CI: 0.3–0.9]), but greater odds of drinking alcohol/using drugs before their last sexual encounter (OR: 4.6 [CI: 1.2–17.6]), currently smoking (OR: 2.3 [CI: 1.2–4.4]), and using smokeless tobacco (OR: 4.6 [CI: 1.2–17.2]). Compared with healthy weight male students, male students with extreme obesity had greater odds of smoking before age 13 (OR: 1.4 [CI: 1.0–2.0]).

CONCLUSIONS:

With few exceptions, HSS with extreme obesity engage in high-risk behaviors at rates comparable with healthy weight peers, sometimes in even more dangerous ways. Health care providers should assess risk-taking behaviors in this cohort.
Impact of Provider Specialty on Pediatric Procedural Sedation Complication Rates
Authors: Couloures Kevin G. , Beach Michael , Cravero Joseph P. , Monroe Kimberly K. , Hertzog James H.
Published: April 2011

OBJECTIVE:

To determine if pediatric procedural sedation-provider medical specialty affects major complication rates when sedation-providers are part of an organized sedation service.

METHODS:

The 38 self-selected members of the Pediatric Sedation Research Consortium prospectively collected data under institutional review board approval. Demographic data, primary and coexisting illness, procedure, medications used, outcomes, airway interventions, provider specialty, and adverse events were reported on a self-audited, Web-based data collection tool. Major complications were defined as aspiration, death, cardiac arrest, unplanned hospital admission or level-of-care increase, or emergency anesthesia consultation. Event rates per 10 000 sedations, 95% confidence intervals, and odds ratios were calculated using anesthesiologists as the reference group and were then adjusted for age, emergency status, American Society of Anesthesiologists physical status > 2, nil per os for solids, propofol use, and clustering by site.

RESULTS:

Between July 1, 2004, and December 31, 2008, 131 751 pediatric procedural sedation cases were recorded; there were 122 major complications and no deaths. Major complication rates and 95% confidence intervals per 10 000 sedations were as follows: anesthesiologists, 7.6 (4.6–12.8); emergency medicine, 7.8 (5.5–11.2); intensivist, 9.6 (7.3–12.6); pediatrician, 12.4 (6.9–20.4); and other, 10.2 (5.1–18.3). There was no statistical difference (P > .05) among provider's complication rates before or after adjustment for potential confounding variables.

CONCLUSIONS:

In our sedation services consortium, pediatric procedural sedation performed outside the operating room is unlikely to yield serious adverse outcomes. Within this framework, no differences were evident in either the adjusted or unadjusted rates of major complications among different pediatric specialists.
Use of Chaperones During the Physical Examination of the Pediatric Patient
Authors: Curry Edward S. ,   Committee on Practice and Ambulatory Medicine
Published: April 2011

This Policy Statement was reaffirmed June 2022.

Physicians should always communicate the scope and nature of the physical examination to be performed to the pediatric patient and his or her parent. This statement addresses the use of chaperones and issues of patient comfort, confidentiality, and privacy. The use of a chaperone should be a shared decision between the patient and physician. In some states, the use of a chaperone is mandated by state regulations.
Brachiaria spp. poisoning of ruminants in Brazil
Authors: Riet-Correa B. , Castro M.B. , Lemos R.A. , Riet-Correa G. , Mustafa V. , Riet-Correa F.
Published: April 2011

Brachiaria species are the most important grasses for cattle production in Brazil. However, a limiting factor for the use of Brachiaria spp. is their toxicity. Most outbreaks of hepatogenous photosensitization are caused by B. decumbens; however B. brizantha, B. humidicola and B. ruziziensis can also cause poisoning. The poisoning affects cattle, sheep, goats and buffalo. Sheep are more susceptible than other animal species and the young are more susceptible than adults. There are differences in susceptibility among animals of the same species and it has been suggested that this resistance is genetic. Also has been suggested that buffalo and probably some sheep are resilient, i.e. when poisoned these animals have histologic lesions and high GGT serum concentrations, but do not show clinical signs. In general, saponin concentrations are higher in growing plants, but outbreaks occur all over the year, probably due to unexplained rise in saponin concentration in the plant. A clinical syndrome of progressive weight loss and death, without photosensitization, has been reported in cattle poisoned by B. decumbens. Main preventive measures are based on the selection of resistant or resilient animals and on the development of Brachiaria species or varieties with low saponin concentration.