Apparent Deficit Research Articles

Intraspinal implantation of hNT neurons into SOD1 mice with apparent motor deficit.

The aim of this study was to determine the effect of hNT neuron transplants on motor neuron function in SOD1 (G93A) mice when motor deficits were already apparent. The hNT neurons were implanted into L(4)-L(5) segments of the ventral horn spinal cord of mice at 15-16 weeks of age: either G93A mice, transgenic mice carrying the normal allele for human SOD1 gene (hTg), or control wild type mice (wt). Behavioral tests (rotorod, beam balance, extension reflex, footprint) were performed prior to transplantation and at weekly intervals afterwards. HNT neuron transplantation in the SOD1 mice delayed disease progression for 3-4 weeks, although lifespan was not affected. These results suggest that hNT neuron transplantation may be a promising therapeutic strategy for ALS in the later phase of the neurodegeneration.

The Rise and Fall of Frequency and Imageability: Noun and Verb Production in Semantic Dementia

This study examines the impact of progressive degeneration of conceptual knowledge on the content words used in connected speech elicited using the Cookie Theft picture description (Goodglass & Kaplan, 1983). We began with an analysis of control subjects' descriptions with regard to word types and their frequency and imageability. Because the impairment of conceptual knowledge in semantic dementia is graded by concept familiarity, we created a model of a standardized normal Cookie Theft description that was then progressively degraded by the systematic removal of lower bands of word frequency. We drew two main predictions from this model: reduced availability of the lower bands of word frequency should result in (a) an apparent deficit for noun retrieval in relation to verb retrieval and (b) an apparent reverse imageability effect. Results from a longitudinal study, in which three patients with semantic dementia each described the Cookie Theft picture on three occasions during the progression of their disease, confirmed these predictions. An additional cross-sectional analysis, adding narratives from a larger number of cases, demonstrated that the decline in ability to produce suitable words for the picture description is closely related to the extent of semantic impairment as measured in tests of word comprehension and production. Both verbs and nouns are affected by the degradation of semantic memory; the fact that the impairment to noun production is manifested earlier and more catastrophically may be attributed to the relatively lower frequency of these terms.

Disorders of human complex sound processing

This review considers reports of patients with disordered complex sound processing. This represents the processing of sound patterns in the spectral, temporal, intensity or spatial domain. Disordered processing of stimuli with particular acoustic structures may be manifest at a higher level as an apparent cognitive deficit, such as word deafness, amusia or environmental sound agnosia. The specific disorder will depend on the domain affected, and the region of that domain.

Human Poliovirus Replicon Vectors in a Murine Model of Spinal Cord Injury

Introduction: Despite great progress in the field of spinal cord injury (SCI) research, the prognosis of patients with acute SCI remains poor. Although growth factors lead to functional improvement in rodent SCI models, limited diffusion and cellular specificity of certain growth factors restrict their efficacy. A significant hurdle for this therapy is targeted delivery to the cells of interest. We are investigating a novel, modified poliovirus replicon delivery system that targets spinal motor neurons. Methods: Using a modified mouse weight-drop SCI model (Kuhn and Wrathall, 1998), we induce moderate SCI at T11 in transgenic mice that express human polio receptor. The resulting functional paraparesis is evaluated by a variety of well-known assessment scales. Immediately after injury, replicons containing the gene for green fluorescent protein (GFP) are injected intrathecally. Intraspinal administration of these replicons in mice does not result in apparent neurological deficit or pathology, nor does it permanently alter the...

Application of Whitney and Nuismer stress fracture criterion to composites loaded in shear

Acknowledgement of the current lack of research conducted upon assessing the damage tolerance of a composite loaded in inplane shear and predictions on residual strengths for this loading condition has provoked attempts to rectify this apparent void in composite research. A literature survey in this field has identified three key issues for this apparent deficit: lack of a suitable test method; difficulty in achieving pure shear, and non-existence of a suitable failure criterion.

Lymphohaematopoietic malignancy around all industrial complexes that include major oil refineries in Great Britain.

OBJECTIVES: To examine the incidence of lymphohaematopoietic malignancy around industrial complexes that include major oil refineries in Great Britain after recent public and scientific concern of possible carcinogenic hazards of...

Budget of [formula omitted] species measured at a coastal site

Concentrations of total NO y as well as the major individual species comprising NO y , i.e. NO, NO 2, PAN, HNO 3, HONO and aerosol nitrate, have been measured in three campaigns at the Weybourne Atmospheric Observatory on the north Norfolk coast in Eastern England. The sum of the individual NO y species ( ∑NO yi ) accounted for a high proportion (typically 96%) of total NO y in the two Winter campaigns carried out, but considerably less (about 79%) in a Summer campaign. It was found that the apparent deficit in ∑NO yi in the summer campaign samples correlated closely with the concentration of NH x (sum of gaseous ammonia and particulate ammonium) and it appears that excessive cleaning of the converter led to a sensitivity to these species. Subtraction of the NH x interference leads to a high degree of closure, close to 100% in morning and nighttime samples and 95% in afternoon samples. Thus, unlike many published studies, there is no substantial “missing” NO y and the small deficit in afternoon samples is probably explicable in terms of unmeasured photochemically generated organic nitrates. The magnitude of the ratio ∑NO yi/ NO y appeared largely independent of the NO y concentration. The NO x/ NO y ratio tended to increase with increased NO y in the full dataset consistent with lesser oxidation of NO x in the more polluted airmasses. This facet was not obvious, however, in a subset of marine airmass samples. On a short timescale, however, the NO x/ NO y ratio can exhibit a strong diurnal cycle. An attempt to simulate this cycle of NO x/ NO y by means of a numerical model was fairly successful, though there was some lowering of the midpoint of the oscillation towards the end of the run. It was also demonstrated that if the rate of diurnally averaged nitric acid deposition were to match its rate of formation from NO 2, a relatively constant NO x/ NO y ratio in time-averaged samples could be explained without invoking atmospheric conversion of HNO 3 to NO 2. Nevertheless, the latter remains a possible explanation for the relative constancy of the NO x/ NO y ratio.

A mutually consistent seismic-hazard source model for southern California

AbstractA previous attempt to integrate geological, geodetic, and observed seismicity data into a probabilistic-hazard source model predicted a rate of magnitude 6 to 7 earthquakes significantly greater than that observed historically. One explanation was that the discrepancy, or apparent earthquake deficit, is an artifact of the upper magnitude limit built into the model. This was controversial, however, because removing the discrepancy required earthquakes larger than are seen in the geological record and larger than implied from empirical relationships between fault dimension and magnitude. Although several articles have addressed this issue, an alternative, integrated source model without an apparent deficit has not yet appeared. We present a simple geologically based approach for constructing such a model that agrees well with the historical record and does not invoke any unsubstantiated phenomena. The following factors are found to be influential: the b-value and minimum magnitude applied to Gutenberg-Richter seismicity; the percentage of moment released in characteristic earthquakes; a round-off error in the moment-magnitude definition; bias due to historical catalog incompleteness; careful adherence to the conservation of seismic moment rate; uncertainty in magnitude estimates obtained from empirical regressions; allowing multi-segment ruptures (cascades); and the time dependence of recurrence rates. The previous apparent deficit is shown to have resulted from a combination of these factors. None alone caused the problem nor solves it. The model presented here is relatively robust with respect to these factors.

Ruptured anterior spinal artery aneurysm: a case report

BACKGROUND Spinal artery aneurysms are rare, and are usually found in association with arteriovenous malformations or coarctation of the aorta. CASE REPORT A 42-year-old man with a ruptured anterior spinal artery aneurysm is presented here. He experienced subarachnoid hemorrhage, which was confirmed by computed tomography. Magnetic resonance imaging revealed an aneurysm in front of the upper part of the medulla. Angiography demonstrated bilateral vertebral artery occlusion. Distal vertebral arteries and the basilar artery were perfused via the dilated anterior spinal artery, which originates in the right subclavian artery. The aneurysm was located at the distal part of the anterior spinal artery, and was successfully clipped through a lateral suboccipital craniotomy 2 months after bleeding from the aneurysm. After rehabilitation, the patient was able to walk with no apparent neurologic deficit. CONCLUSIONS This case suggests that the anterior spinal artery as a collateral route after bilateral vertebral arery occlusion is under hemodynamic stress, resulting in aneurysm formation and rupture.

Inheritance of nuclear DNA markers in gynogenetic haploid pink salmon.

We describe the inheritance of 460 PCR-based loci in the polyploid-derived pink salmon (Oncorhynchus gorbuscha) genome using gynogenetic haploid embryos. We detected a length polymorphism in a growth hormone gene (GH-2) intron that is caused by an 81 bp insertion homologous to the 3' end of the salmonid short interspersed repetitive element (SINE) SmaI. Such insertion polymorphisms within species bring into question the use of SINEs as phylogenetic markers. We confirmed that a microsatellite locus encodes a PCR-null allele that is responsible for an apparent deficit of heterozygotes in a population sample from Prince William Sound. Another set of microsatellite primers amplified alleles of the same molecular weight from both loci of a duplicated pair. In our analysis of several PCR-based multilocus techniques, we failed to detect evidence of comigrating fragments produced by duplicated loci. Segregation analysis of PCR-based markers using gynogenetic haploid embryos ensures that the interpretation of molecular variation is not complicated by heterozygosity, diploidy, or gene duplication. We urge investigators to test the inheritance of polymorphisms in salmonids prior to using them to measure genetic variation.

Patterns of historical earthquake rupture in the Iranian Plateau

Abstract The Iranian plateau accommodates the 35 mm/yr convergence rate between the Eurasian and Arabian plates by strike-slip and reverse faults with relatively low slip rates in a zone 1000 km across. Although these faults have only locally been the subject of paleoseismological studies, a rich historical and archeological record spans several thousand years, long enough to establish recurrence intervals of 1000 to 5000 yr on individual fault segments. Several clusters of earthquakes provide evidence of interaction among reverse and strike-slip faults, probably due to adjacent faults being loaded by individual earthquakes. The Dasht-e-Bayaz sequence of 1936 to 1997 includes earthquakes on left-lateral, right-lateral, and reverse faults. The Neyshabur sequence of four earthquakes between 1209 and 1405 respected the segment boundary between the Neyshabur and Binalud reverse fault systems. The two pairs of earthquakes may have ruptured different faults in each segment, similar to the 1971 and 1994 San Fernando, California, earthquakes. The 1978 Tabas reversefault earthquake was preceded by the 1968 Ferdows earthquake, part of the Dasht-e-Bayaz sequence. The North Tabriz fault system ruptured from southeast to northwest in three earthquakes from 1721 to 1786; a previous cluster may have struck this region in 855 to 958. The Mosha fault north of Tehran ruptured in three earthquakes in 958, 1665, and 1830. Five large earthquakes struck the Tehran region from 743 to 1177, but only two that large have struck the area since 1177. Other earthquakes occurred in pairs in the Talesh Mountains near the Caspian Sea (1863, 1896), the Iran-Turkey border (1840, 1843), and the Nayband-Gowk fault system (both in 1981). Other historical events did not occur as parts of sequences. The historic seismic moment release in Iran accounts for only a small part of the plate convergence rate, which may be due to aseismic slip or to the Iranian historical record, long as it is, being too short to sample long-term deformation across the plateau. No historic earthquakes of M ≧ 8 have struck Iran. However, several long, straight strike-slip faults (Doruneh, West Neh, East Neh, and Nayband) have not sustained large historical earthquakes, raising the possibility that these long faults could produce earthquakes of M ≧ 8, thereby removing at least part of the apparent slip deficit. An increased understanding of Iran's seismic hazard could be obtained by an extensive paleoseismology program and space-geodetic arrays, supplementing the abundant historical and archaeological record.

A Photometric Survey for Low‐Mass Members of IC 2391

ABSTRACTA VRI photometric survey has been conducted in the young open cluster IC 2391 to identify candidate low‐mass cluster members. Photometry for some 10,725 objects, ranging from V = 10 to V = 20, were extracted from 21 CCD fields positioned within 1° of the nominal cluster center[α(2000) = 08h42m, δ(2000) = -53°00′]. Seventeen stars have been identified as candidate cluster members with (V−I) colors ranging from 2.78 to 3.72. The masses of these candidate members are estimated to range from 0.25 to 0.09 M⊙. If these stars are indeed IC 2391 members, they will help to rectify an apparent deficit of low‐luminosity stars in the luminosity function of this cluster.

Striatal lesions produce distinctive impairments in reaction time performance in two different operant chambers

The dorsal striatum plays a crucial role in mediating voluntary movement. Excitotoxic striatal lesions in rats have previously been shown to impair the initiation but not the execution of movement in a choice reaction time task in an automated lateralised nose-poke apparatus (the “nine-hole box”). Conversely, when a conceptually similar reaction time task has been applied in a conventional operant chamber (or “Skinner box”), striatal lesions have been seen to impair the execution rather than the initiation of the lateralised movement. The present study was undertaken to compare directly these two results by training the same group of rats to perform a choice reaction time task in the two chambers and then comparing the effects of a unilateral excitotoxic striatal lesion in both chambers in parallel. Particular attention was paid to adopting similar parameters and contingencies in the control of the task in the two test chambers. After striatal lesions, the rats showed predominantly contralateral impairments in both tasks. However, they showed a deficit in reaction time in the nine-hole box but an apparent deficit in response execution in the Skinner box. This finding confirms the previous studies and indicates that differences in outcome are not simply attributable to procedural differences in the lesions, training conditions or tasks parameters. Rather, the pattern of reaction time deficit after striatal lesions depends critically on the apparatus used and the precise response requirements for each task.

Is There a Deficit of S0 Galaxies at Intermediate Redshift?

Two contradictory results on the evolution of SO galaxies now exist in the recent literature: either S0's are old (zformation > 2) and are evolving passively or most of them form at z < 0.5, as implied by the deficit of S0's in intermediate-redshift (z ~ 0.5) clusters. The resolution of this controversy may be that the apparent deficit of S0's has been derived from a quantity—the E-to-S0 ratio—that is prone to morphological classification errors. Once all sources of error are taken into account, the E-to-S0 ratios of clusters at different redshifts are fully compatible, and no additional creation of S0's at z < 0.5 is required by the data. Furthermore, there is no deficit at all of S0's in the intermediate-redshift cluster for which we have morphological types of very high quality and thus derive an E-to-S0 ratio with a small error.

Habitual nutrient intake and energy expenditure of students participating in recreational sports

The purpose of this study was to assess the energy expenditure and nutrient intake of students. Data was collected in the form of four-day-activity and diet diaries from basketball players of the university level and also from students not participating in sports regularly. The energy intake of the male basketball players (MBP, n=7) in comparison with the energy expenditure was 64% and 108% in training and resting days, respectively. The corresponding values for the female basketball players (FBP, n=7) were 55% and 81%. The energy intake of female students not participating in sports (FNP, n=10) made up 80% of their energy expenditure. The proportions of energy obtained from each major nutrient did not differ essentially on resting and training days and were similar for FBP and MBP: carbohydrates 43.0–48.4%, proteins 11.4–13.0%, fats 40.2–44.1%. For FNP the corresponding values were 52.2%, 12.5% and 35.4%. The mean daily Ca intake on training days was only 692 mg and 561 mg in MBP and FBP, respectively. The mean Fe intake was 15–21 mg per day in all groups. These results demonstrated apparent energy deficit in student basketball players on training days, as well as unbalanced nutrient composition (excess fat and low Ca content) of their habitual diet.

Patients with Primary Osteoarthritis Show No Change with Ageing in the Number of Osteogenic Precursors

The variation in marrow colony forming unit-fibroblastic (CFU-F) number in 59 patients (14-87 years of age) undergoing corrective surgery (14 controls; 14-48 years of age) or hip arthroplasty for primary osteoarthritis (45 OA; 46-87 years of age) was examined to determine whether marrow CFU-F, derived from marrow stromal fibroblastic stem cells, are maintained with the development of primary osteoarthritis (OA). Total colony number, colony size as well as alkaline phosphatase-positive colonies were determined. The mean fibroblast colony forming efficiency from the whole patient group was 2.4 x 10(-5) +/- 1.4 x 10(-5). Ageing had no effect on the colony forming efficiency or on the alkaline-phosphatase-positive colony forming efficiency, irrespective of gender. Thus precursor cells with the potential for osteogenic differentiation are maintained in OA with ageing. However, colony size showed a significant reduction with age, implying altered proliferation potential of osteogenic progenitors with ageing. This ageing effect may not be as significant in OA as in the rest of the population as bone mineral density is often preserved in osteoarthritis. As there is no apparent deficit in primitive progenitor cells, this preservation may be the result of altered regulation of osteoprogenitor activity in OA.

Developmental word-finding difficulties and phonological processing: The case of the missing handcuffs

ABSTRACTThe case of a 7-year-old boy (Michael) with severe word-finding difficulties is presented. In an attempt to investigate the cause of these difficulties, a series of theoretically motivated questions was used as a framework for psycholinguistic investigation. A range of tasks was administered, including word association, semantic knowledge, auditory discrimination, auditory lexical decision, naming, and real word and nonword repetition. Michael's performance on the tasks was compared with that of controls matched in terms of chronological and vocabulary age. Results revealed significant differences between Michael's performance and that of the control groups. Although he showed no apparent semantic deficit, he did show pervasive deficits in phonological processing.

Oculomotor response inhibition abnormalities in pediatric obsessive-compulsive disorder.

Disturbances in the orbital prefrontal cortex and its ventral striatal target fields have been identified in neuroimaging studies of obsessive-compulsive disorder (OCD). In animal models and studies of patients with lesions to this brain circuitry, a selective disturbance in the ability to suppress responses to irrelevant stimuli has been demonstrated. Such a deficit in response suppression might underlie the apparent inhibitory deficit suggested by the symptoms of OCD. To date, little direct evidence of such a deficit has been reported. Further, although OCD commonly emerges during childhood or adolescence, few studies have examined psychotropic-naive pediatric patients near the onset of illness to find the possible role of atypical developmental processes in this disorder. Oculomotor tests were administered to 18 psychotropic medication-naive, nondepressed patients with OCD aged 8.8 to 16.9 years and 18 case-matched healthy comparison subjects to assess the following 3 well-delineated aspects of prefrontal cortical function: the ability to suppress responses, the volitional execution of delayed responses, and the anticipation of predictable events. A significantly higher percentage of response suppression failures was observed in patients with OCD (P = .003), particularly in younger patients compared with their case-matched controls. No significant differences between patients with OCD and controls were observed on other prefrontal cortical functions. Severity of OCD symptoms was related to response suppression deficits. A basic disturbance of behavioral inhibition in OCD was detected that may underlie the repetitive symptomatic behavior that characterizes the illness.

SEISMICITY AND STRAIN IN THE GULF OF CORINTH (GREECE) SINCE 1694

We use the record of earthquakes in central Greece since 1694 to estimate the seismically-released strain in that region over the last 300 years. The highest strain rate is seen in the Gulf of Corinth, an extensional graben which is the most prominent active geological structure. Over the 300-year period, the earthquakes account for an average extension rate of about 11 ram/yr between the Peloponnese and the island of Evvia, of which about 10 mm/yr occurs in the Gulf of Corinth. The earthquakes occurring in shorter time periods, perhaps as little as 100 years, account for extensional velocities similar to the 300 year average, though the 20th Century has been relatively quiescent. We are not confident that the historical record can be used to assess seismic strain release in areas smaller than the Gulf of Corinth as a whole. The similarity between the average rate of seismic strain release over 300 years and the short-term strain rates measured geodetically suggests that the bulk of the tectonic strain in this region is released by seismic slip on faults, and that aseismic creep is relatively unimportant. An apparent deficit in seismic strain release over a short period (as is observed for the 20th Century) is thus likely to be remedied by future earthquakes.

Sensory effects of microvascular decompression in trigeminal neuralgia

Nineteen patients with "idiopathic" trigeminal neuralgia, who had not undergone any previous interventional procedures, possessed a vessel or vessels compressing the preganglionic nerve root that was demonstrated by magnetic resonance tomographic angiography. Pain was relieved immediately in all of these patients after they underwent microvascular decompression without observed nerve damage. Although preoperative measurement of sensory perception thresholds showed elevations in the thresholds for touch (von Frey filaments) and warmth and coolness sensations, these thresholds normalized during the postoperative period. An apparent deficit in the pinprick (sharpness) sensation appeared postoperatively, but the deficit gradually regressed and completely disappeared by 1 year after surgery; this phenomenon may have been a statistical anomaly. The patients' pain disappeared immediately postoperatively and remained absent throughout the follow-up period. The authors conclude that damage to the nerve or nerve root is not essential for the relief of trigeminal neuralgia.