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Optimal conditions of development have been of interest for decades, since genetics alone cannot fully explain how an individual matures. In the present study, we used optical brain imaging to investigate whether a relatively simple enrichment can positively influence the development of the visual cortex of mice. The enrichment paradigm was composed of larger cages housing multiple mice that contained several toys, hiding places, nesting material and a spinning wheel that were moved or replaced at regular intervals. We compared C57BL/6N adult mice (> P60) that had been raised either in an enriched environment (EE; n = 16) or a standard (ST; n = 12) environment from 1 week before birth to adulthood, encompassing all cortical developmental stages. Here, we report significant beneficial changes on the structure and function of the visual cortex following environmental enrichment throughout the lifespan. More specifically, retinotopic mapping through intrinsic signal optical imaging revealed that the size of the primary visual cortex was greater in mice reared in an EE compared to controls. In addition, the visual field coverage of EE mice was wider. Finally, the organization of the cortical representation of the visual field (as determined by cortical magnification) versus its eccentricity also differed between the two groups. We did not observe any significant differences between females and males within each group. Taken together, these data demonstrate specific benefits of an EE throughout development on the visual cortex, which suggests adaptation to their environmental realities. [ABSTRACT FROM AUTHOR]

Background: Chronic obstructive pulmonary disease (COPD) has been proposed as a disease of accelerated aging. Several cross-sectional studies have related a shorter telomere length (TL), a marker of biological aging, with COPD outcomes. Whether accelerated telomere shortening over time relates to worse outcomes in COPD patients, is not known.Methods: Relative telomere length (T/S) was determined by qPCR in DNA samples from peripheral blood in 263 patients at baseline and up to 10 years post enrolment. Yearly clinical and lung function data of 134 patients with at least two-time measures of T/S over this time were included in the analysis.Results: At baseline, T/S inversely correlated with age (r = - 0.236; p < 0.001), but there was no relationship between T/S and clinical and lung function variables (p > 0.05). Over 10 years of observation, there was a median shortening of TL of 183 bp/year for COPD patients. After adjusting for age, gender, active smoking and mean T/S, patients that shortened their telomeres the most over time, had worse gas exchange, more lung hyperinflation and extrapulmonary affection during the follow-up, (PaO2 p < 0.0001; KCO p = 0.042; IC/TLC p < 0.0001; 6MWD p = 0.004 and BODE index p = 0.009). Patients in the lowest tertile of T/S through the follow-up period had an increased risk of death [HR = 5.48, (1.23-24.42) p = 0.026].Conclusions: This prospective study shows an association between accelerated telomere shortening and progressive worsening of pulmonary gas exchange, lung hyperinflation and extrapulmonary affection in COPD patients. Moreover, persistently shorter telomeres over this observation time increase the risk for all-cause mortality. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Sport & Health Research is the property of Journal of Sport & Health Research and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Despite the fact that in the last decades, several mental health studies have shown that companion animals contribute to psychological and social well-being in humans (e.g., positive impacts have been observed in the elderly medicated for chronic diseases such as anxiety, dementia, and depression), bonds between humans and other animals continue to be underestimated. The aim of this study is to assess the impact of an animal's visits (twice a week, N = 30) in depression and anxiety levels of an institutionalized male population diagnosed with dementia. While some of these patients are being partially medicated with antidepressants and/or anxiolytics, others are not subject to any medication (control group). The GAI and GDS measuring instruments were used and there were differences in anxiety and depression levels between the first and last dog visit, statistically significant in depression levels of nonmedicated patients. Such findings allow us to conclude that the effects of the visits of an animal near nonmedicated patients are greater than near medicated ones. The complementary role of animals in mental health institutions where patients are being treated for psychiatric disorders (in the particular case of dementia) should be considered. [ABSTRACT FROM AUTHOR]

The dispersion and stability of nanofluids obtained by dispersing Al2O3 nanoparticles (obtained from different sources) in water have been analyzed. The differences arising from different dispersion techniques, the resulting particle size distribution, and time stability among the different samples are evaluated. Then the volumetric behavior up to high pressures (25 MPa) and atmospheric pressure viscosity were experimentally determined. It has been found that the influence of particle size in density is subtle but not negligible, but the differences in viscosity are very large and must be taken into account for any practical application. These viscosity differences can be rationalized by considering a theory describing the aggregation state of the nanofluid. [ABSTRACT FROM AUTHOR]

Objective: To describe our experience in first-trimester screening for trisomies 21 and 18 firstly by the combined test alone and secondly by cell-free (cf) DNA testing contingent on the results from a previously performed combined test.Methods: Women with singleton pregnancies attending Torrejon University Hospital in Madrid, Spain, from November 2011 to January 2016, were screened for trisomy (T)21 and T18 by the combined test at 11-13 weeks. Before the introduction of cfDNA testing, women at high risk (>1 in 250) were offered invasive testing (IT) and from January 2015 they were offered cfDNA test as well as IT.Results: Combined test was performed in 6011 pregnancies. The risk was high in 202 (3.4%) cases. There was complete follow-up for 5507 (91.6%) pregnancies. Detection rate (DR) for T21 was 83.3% (15/18) and 100% (4/4) for T18. Additionally, 2/2 (100%) cases of T13 and 2/2 (100%) cases of triploidy were also detected. False positive rate (FPR) was 3.2% (174/5488). The introduction of this contingent model was followed by a 73% reduction on the IT rate in the high-risk group, from 76.3% to 20.8%.Conclusion: Contingent screening for trisomies 21 and 18 by cfDNA testing at 11-13 weeks is feasible and has a lower IT rate than combined testing alone. [ABSTRACT FROM AUTHOR]

The disease caused by Tomato leaf curl New Delhi virus ( ToLCNDV), which is naturally transmitted by the whitefly Bemisia tabaci, causes important economic losses in cucurbit crops. The availability of simple and efficient inoculation protocols and detection methods is necessary for screening varieties and germplasm collections as well as for breeding populations. We evaluated the infectivity of ToLCNDV inocula prepared using three different buffers for mechanical sap inoculation in a susceptible variety of zucchini. We found that inoculum prepared with buffer III, which contains polyvinylpyrrolidone, is highly efficient for mechanical inoculation, with 100% of plants displaying severe symptoms 21 days post-inoculation. Using this buffer, we mechanically inoculated 19 commercial varieties of cucurbit crops (six of cucumber, six of melon and seven of zucchini), evaluated the evolution of symptoms and diagnosed infection using nine different ToLCNDV detection methods (four based on serology, four based on molecular hybridization and one based on PCR detection). The results revealed that all varieties are susceptible, although cucumber varieties display less severe symptoms than those of melon or zucchini. All detection methods were highly efficient (more than 85% of plants testing positive) in melon and zucchini, but in cucumber, the percentage of positive plants detected with serology and molecular hybridization methods ranged from 20.4% with Squash leaf curl virus ( SLCV) antiserum, to 78.5% with DNA extract hybridization. Overall, the best detection results were obtained with PCR, with 92.6%, 92.4% and 98.4% cucumber, melon and zucchini plants, respectively, testing positive. When considering the overall results in the three crops, the best serology and molecular hybridization methods were those using Watermelon chlorotic stunt virus ( WmCSV) antiserum and DNA extract, respectively. The inoculation methodology developed and the information on detection methods are of great relevance for the selection and breeding of varieties of cucurbit crops that are tolerant or resistant to ToLCNDV. [ABSTRACT FROM AUTHOR]

Copyright of Revista Andaluza de Medicina del Deporte is the property of Centro Andaluza de Medicina del Deporte and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Ultrasound in Obstetrics & Gynecology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Guinea baboons are heavily hunted for bushmeat consumption in Guinea-Bissau. We investigated whether hunting-driven mortality has affected population structure in this generalist primate using two genetic markers. Sampling was conducted in protected areas separated by anthropogenic landscape features. We predicted significant genetic differentiation between samples and investigated whether genetic discontinuities in the data were concordant with the location of human infrastructures. Genetic diversity was not significantly reduced when compared with a neighbouring population in Senegal and we inferred historically female-biased dispersal and recent contact between localities. Evidence was found for a contact zone between genetically differentiated populations where gene-flow is unidirectional, admixed individuals are at a higher proportion and individuals differentiated for both genetic markers co-exist within the same social units. Genetic discontinuities were, however, unrelated to anthropogenic dispersal barriers and we could not explain the existence of a contact zone by geographic distance, habitat type or the effect of social structure. We propose that hunting practices have affected the population structure by increasing dispersal distances, facilitating contact between previously separated gene pools within social groups. We suggest that hunting-related density sinks found in areas where the quality of the habitat remains adequate could precipitate the immigration of genetically distinct individuals from distant populations. Alternatively, migrants found in protected areas might be avoiding hunters, in locations they may perceive as less disturbed. This study suggests that hunting practices must be considered when investigating genetic patterns in primates and underlines the utility of molecular approaches to detect population perturbations due to bushmeat hunting. [ABSTRACT FROM AUTHOR]

Plaid stimuli are often used to investigate the mechanisms involved in the integration and segregation of motion information. Considering the perceptual importance of such mechanisms, only a very limited number of visual brain areas have been found to be specifically involved in motion integration. These are the human (h)MT+ complex, area V3 and the pulvinar. The hMT+ complex can be functionally subdivided into two separate areas, middle temporal area (MT) and medial superior temporal area (MST); however, it is currently unclear whether these distinct sub-regions have different responses to plaid stimuli. To address this issue we used functional magnetic resonance imaging to quantify the relative response of MT and MST to component and pattern motion. Participants viewed plaid stimuli that were constrained to result in the perception of either component motion (segregation of motion information) or pattern motion (integration of motion information). MT/MST segregation was achieved using a moving dot stimulus that allowed stimulation of each visual hemifield either in unison or separately. We found pattern motion selective responses in both MT and MST. Consistent with previous reports, activity indicative of pattern motion selectivity was also found in the pulvinar as well as in other extrastriate areas. These results demonstrate that MT, MST and the pulvinar are involved in the complex motion integration mechanisms that are triggered by plaid stimuli. This reinforces the concept that integrative computations take place in a distributed neuronal circuit both in cortical and sub-cortical networks. [ABSTRACT FROM AUTHOR]

RATIONALE: Chronic obstructive pulmonary disease (COPD) is thought to result in rapid and progressive loss of lung function usually expressed as mean values for whole cohorts. OBJECTIVES: Longitudinal studies evaluating individual lung function loss and other domains of COPD progression are needed. METHODS: We evaluated 1,198 stable, well-characterized patients with COPD (1,100 males) recruited in two centers (Florida and Tenerife, Spain) and annually monitored their multidomain progression from 1997 to 2009. Patients were followed for a median of 64 months and up to 10 years. Their individual FEV(1) (L) and BODE index slopes, expressed as annual change, were evaluated using regression models for repeated measures. A total of 751 patients with at least three measurements were used for the analyses. MEASUREMENTS AND MAIN RESULTS: Eighteen percent of patients had a statistically significant FEV(1) slope decline (-86 ml/yr; 95% confidence interval [CI], -32 to -278 ml/yr). Higher baseline FEV(1) (relative risk, 1.857; 95% CI, 1.322-2.610; P < 0.001) and low body mass index (relative risk, 1.071; 95% CI, 1.035-1.106; P < 0.001) were independently associated with FEV(1) decline. The BODE index had a statistically significant increase (0.55, 0.20-1.37 point/yr) in only 14% of patients and these had more severe baseline obstruction. Concordance between FEV1 and BODE change was low ([kappa] Cohen, 16%). Interestingly, 73% of patients had no significant slope change in FEV1 or BODE. Only the BODE change was associated with mortality in patients without FEV(1) progression. CONCLUSIONS: The progression of COPD is very heterogeneous. Most patients show no statistically significant decline of FEV(1) or increase in BODE. The multidimensional evaluation of COPD should offer insight into response to COPD management. [ABSTRACT FROM AUTHOR]

RATIONALE: Little is known about the clinical factors associated with the development of lung cancer in patients with chronic obstructive pulmonary disease (COPD), although airway obstruction and emphysema have been identified as possible risk factors. OBJECTIVES: To explore incidence, histologic type, and factors associated with development of lung cancer diagnosis in a cohort of outpatients with COPD attending a pulmonary clinic. METHODS: A cohort of 2,507 patients without initial clinical or radiologic evidence of lung cancer was followed a median of 60 months(30-90). At baseline, anthropometrics, smoking history, lung function,and body composition were recorded. Time to diagnosis and histologic type of lung cancer was then registered. Cox analysis was used to explore factors associated with lung cancer diagnosis. MEASUREMENTS AND MAIN RESULTS: A total of 215 of the 2,507 patients with COPD developed lung cancer (incidence density of 16.7 cases per 1,000 person-years). The most frequent type was squamous cell carcinoma (44%). Lung cancer incidence was lower in patients with worse severity of airflow obstruction. Global Initiative for Chronic Obstructive Lung Disease Stages I and II, older age, lower body mass index,and lung diffusion capacity of carbon monoxide less than 80%were associated with lung cancer diagnosis. CONCLUSIONS: Incidence density of lung cancer is high in outpatients with COPD and occurs more frequently in older patients with milder airflow obstruction (Global Initiative for Chronic Obstructive Lung Disease Stages I and II) and lower body mass index. A lung diffusion capacity of carbon monoxide less than 80% is associated with cancer diagnosis. Squamous cell carcinoma is the most frequent histologic type. Knowledge of these factors may help direct efforts for early detection of lung cancer and disease management. [ABSTRACT FROM AUTHOR]

Background To evaluate disease-specific health-related quality of life (HRQoL) in patients with symptomatic esophageal achalasia before and after therapy. Methods Symptoms and disease-specific HRQoL were evaluated before and 3 months after therapy. Therapy selection, either dilatation or myotomy, depended exclusively on the opinion of the physician on charge of the patient. Symptom severity was graded from 0 to 3, using a scoring system. A disease-specific questionnaire for achalasia developed and validated in Spanish language with 18 items and four subscales (AE-18) was used to evaluate HRQoL. Changes after therapy in HRQoL and its association with clinical improvement were analyzed. Key Results Sixty-five patients were prospectively included in eight hospitals in Spain. Of them, 47 were treated with dilatation, and 18 with laparoscopic Heller myotomy. After therapy, AE-18 global and subscales scores improved significantly. Changes in HRQoL were associated with improvement in symptoms. An important improvement in symptoms (≥50%) was needed to obtain a minimal clinically important improvement (≥20%) in HRQoL. Conclusions & Inferences Disease-specific HRQoL improves in patients with symptomatic achalasia after therapy with dilatation or myotomy. The degree of improvement of HRQoL depends on the degree of improvement of esophageal symptoms. [ABSTRACT FROM AUTHOR]

The aim of this work was the adaptation and improvement of a previous cloud detection and classification algorithm that was developed for the Meteosat-7 satellite. The functions of this satellite have now been taken on by the new series of Meteosat Second Generation (MSG) satellites, which are not just replicas but new, much improved versions of their predecessor. The formerly used Advanced/Tiros-N Operational Vertical Sounder (A/TOVS) probe has also been superseded technologically by new sensors with better spatial resolution, capable of carrying out more accurate measurements at a greater number of wavelengths. This is the case of the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor onboard the TERRA and AQUA satellites and of the Atmospheric Infrared Sounder (AIRS) probe. In this context, new potential improvements are analysed for this algorithm by using these new platforms and sensors and the results are compared to those obtained in the first classification. [ABSTRACT FROM AUTHOR]

Rationale: The distance walked in the 6-min walk test (6MWT) predicts mortality in patients with severe COPD. Little is known about its prognostic value in patients with a wider range of COPD severity, living in different countries, and the potential additional impact of oxygen desaturation measured during the test.Methods: We enrolled 576 stable COPD outpatients in Spain and the United States and observed them for at least 3 years (median, 60 months). We measured FEV1, body mass index, Pao2, Charlson comorbidity score, 6-min walk distance (6MWD), and oxygen saturation by pulse oximetry (Spo2) during the 6MWT. Desaturation was defined as a fall in Spo2 > or = 4% or Spo2 < 90%. Regression analysis helped determine the association between these variables and all-cause and respiratory mortality.Results: The 6MWD was a good predictor of all-cause and respiratory mortality primarily in patients with FEV1 < 50% of predicted (p < 0.001) after adjusting for all covariates. Patients with desaturation during the 6MWT had a higher mortality rate than patients without desaturation (67% vs 38%, p < 0.001). Oxygen desaturation predicted mortality (relative risk, 2.63; 95% confidence interval, 1.53 to 4.51; p < 0.001) but with less power than Pao2 at rest.Conclusions: The 6MWD helps predict mortality primarily in patients with severe COPD. Although the oxygen desaturation profile during the 6MWT improves the predictive ability of the 6MWD, it appears to be of less relevance than in other lung diseases and than the resting Pao2. [ABSTRACT FROM AUTHOR]

We present evidence of agonistic buffering in captive chimpanzees, recorded from 1993 until 2005, mainly from ad libitum sampling in over 2000 hr of observation. A total of 33 agonistic buffering episodes were analyzed for context and effects of this complex social behavior. Agonistic buffering was directed at the whole chimpanzee colony as they supported an individual who initially received aggression from the alpha male, independently of the victim's age, sex or social rank. Chimpanzee agonistic buffering behavior is compared with that in other nonhuman primate species, and we describe some particularities of chimpanzee agonistic buffering: the status of the buffers used—socially important offspring such as those from the alpha female—and the social rank of the adult male responsible for the buffering episode—alpha male. Possible functions for this behavior in chimpanzees are suggested as appeasement of group members in a particularly crowded captive setting, and/or as a “forced reconciliation” mechanism. Chimpanzees exhibit behavioral flexibility by adapting themselves to new social and physical situations and use novel behavior to achieve social benefits. Am. J. Primatol. 70:54–61, 2008. © 2007 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

During the second half of the month of June 1997, a massive catch of red tuna (Thunnus thynnus) took place off the coast of Babarte (Spain), in contrast to the first half of that month when there was hardly any presence of this species. The aim of this paper was to examine the relation between the high fishing productivity and the meteorological conditions under which the oceanic events to which the tuna fisheries were attracted took place. This was carried out through the analysis of Advanced Very High Resolution Radiometer (AVHRR) sensor data and the data from the Tiros-N Operational Vertical Sounder (TOVS) probe of the NOAA-14 satellite from 10 to 24 June 1997. Results show that the formation of the fishing front was caused by an ocean-atmosphere energetic exchange, which was localized and described through the data transmitted from the NOAA satellites. [ABSTRACT FROM AUTHOR]

In cats, the postero-medial part of lateral suprasylvian cortex (PMLS) is generally considered a key area for motion processing. While behavioral studies have indeed supported the role of PMLS cortex in higher order motion integration (Cereb Cortex 6:814–822, ), there is no evidence that individual PMLS cells can perform such analysis (Vis Neurosci 5:463–468, ; J Neurophysiol 63:1529–1543, ). Given the fundamental importance of understanding the neural substrate subtending higher order motion processing, we investigated whether PMLS neurons can signal the direction of motion of complex random dot kinematograms (RDKs) wherein comprising elements do not provide any local coherent motion cues. Results indicated that most PMLS cells (82%) can integrate the displacement of individual elements into a global motion percept. Their large receptive fields allowed the integration of motion for elements separated by large spatial intervals (up to 4°). In most cases, the analysis of complex RDK motion necessitated the contribution of the area of the visual field beyond the classical receptive field. None of the complex RDK-sensitive cells were found to be pattern-motion selective when tested with plaid patterns. Our results provide the first evidence that receptive fields of PMLS neurons can perform global motion analysis and support the behavioral evidence that this area is implicated in complex motion processing (Cereb Cortex 6:814–822, ). It also further corroborates the findings that PMLS neurons cannot signal the true direction of a plaid pattern (Vis Neurosci 5:463–468, ; J Neurophysiol 63:1529–1543, ). Providing that these same neurons can signal the direction of complex RDKs, there may be distinct cortical mechanisms for processing different types of complex motion. [ABSTRACT FROM AUTHOR]

The aim of this work is to show an automatic method of cloud classification for direct application in civil aviation. We start from the premise of an acceptable trade-off between calculation speed and accuracy in the output data. For this reason, visible and infrared channels of the Meteosat satellite were used alongside data provided by the A/TOVS (Advanced/Tiros-N Operational Vertical Sounder) probe onboard NOAA (National Oceanic and Atmospheric Administration) polar satellites. A historical database of mean temperatures at ground level was also used. The analysis of different significant synoptic and mesoscale situations highlighted the efficacy of this method in the representation of the different cloud structures that normally appear in these situations. Considering the results of the study and given its speed and accuracy, it can be concluded that the method is appropriate for monitoring cloud systems in real time. [ABSTRACT FROM AUTHOR]

Static lung hyperinflation has important clinical consequences in patients with chronic obstructive pulmonary disease. We analyzed the power of lung hyperinflation as measured by the inspiratory capacity-to-total lung capacity ratio (IC/TLC) to predict mortality in a cohort of 689 patients with chronic obstructive pulmonary disease (95% males; FEV[1], 1.17 L) with a mean follow-up of 34 months. We also compared the predictive value of IC/TLC with that of the BODE (body mass index, airflow obstruction, dyspnea, exercise performance) Index. Subjects who died (183; 27%) were older; had lower body mass index, FEV[1], and IC/TLC ratio; walked less in the 6-minute walking distance; and had more dyspnea, a higher BODE Index, and comorbidity (p < 0.001). On the basis of logistic regression analysis, IC/TLC was found to be a good and independent predictor of all-cause and respiratory mortality. On the basis of receiver operating characteristic Type II curves, IC/TLC compared favorably with FEV[1] and predicted mortality independently of the BODE Index. We conclude that IC/TLC is an independent risk factor for mortality in subjects with chronic obstructive pulmonary disease. We propose that this ratio be considered in the assessment of patients with chronic obstructive pulmonary disease. [ABSTRACT FROM AUTHOR]

The saturated heat capacities of benzene and of some linear (toluene, ethylbenzene, propylbenzene, butylbenzene, hexylbenzene, 1-phenylheptane, and 1-phenylhexadecane) and branched (m-xylene, cumene, sec-butylbenzene, tert-butylbenzene, and isobutylbenzene) alkyl-benzenes have been measured. A Micro DSC II from Setaram (France) with batch cells designed in our laboratory, and the "scanning or continuous method," have been used to perform the measurements. The estimated uncertainty of the saturated heat capacities was better than 0.3%. In the literature there exists c[sub sat](T) data for some of the liquids studied. Agreement with our measurements is better than 0.5%. For linear alkyl-benzenes and for each temperature, the variation in the saturated heat capacity with the alkyl length is nearly linear. The selected branched alkyl-benzenes are isomers of the linear alkyl-benzenes studied; accordingly, the influence of molecular structure on the saturated heat capacities has been analyzed. [ABSTRACT FROM AUTHOR]

The effects of early, unilateral cerebral hemispherectomy on retinogeniculate projections were studied in the vervet monkey (Cercopithecus aethiops sabeus).Hemispherectomy eliminates all geniculocortical pathways and thus removes cortical factors involved in the survival of retinogeniculate projections. Complete removal of the left cerebral cortex was performed in two monkeys at 6 months and 8 months of age. After a postsurgical survival period of 50 months (SHG3) and 45 months (SHG4), both animals and a normal adult monkey received intraocular injections of [3H]proline (5 mCi) in the left eye and WGA-HRP (100 µl, 5%) in the right eye. The dorsal lateral geniculate nucleuseuron (LGNd) ipsilateral to the hemispherectomy was on average 73% smaller than the contralateral LGNd. The magno- and parvocellular layers ipsilateral to the cortical ablation in both hemispherectomized subjects received a layered, eye-specific pattern of retinal input. This suggests that retinogeniculate projections could be sustained in the absence of geniculate relay cells. [ABSTRACT FROM AUTHOR]

A study was made of the genetic variability of 101 barley populations belonging to the four, wild, Spanish species of the genus Hordeum (the autogamous H. marinum subspp. marinum and gussoneanum, and H. murinum subspp. murinum and leporinum, plus the allogamous species H. bulbosum and H. secalinum). Electrophoresis of endosperm proteins was performed using a large number of individuals from each population sampled, in order to determine intra- and interpopulational variation. The distribution of variability observed by population and taxonomic unit, is closely related to the breeding system. Hordeum bulbosum showed the greatest intrapopulational variability and H. marinum subsp. gussoneanum the least. In contrast to the autogamous species, the allogamous species showed low levels of interpopulational variation. [ABSTRACT FROM AUTHOR]

Sixteen Triticeae species of the genera Aegilops L., Pseudoroegneria (Nevski) Löve, Taeniatherum Nevski and Thinopyrum Löve were investigated by PCR amplification for the presence of a wheat germin gene internal domain involved in osmotic stress resistance. In all of the species studied a single band of identical or very similar size was detected, After cloning and sequencing of these fragments, different degrees of homology were found with the original wheat domain, which suggested that in these species there are functional differences in the osmotic response involving the germin core. [ABSTRACT FROM AUTHOR]

The genetic variation of 102 natural populations of wild barley growing in Spain was assessed using RAPDs (random amplified polymorphic DNA). The plant material included the annual species H. marinum subsp. marinum (22 populations) and subsp. gussoneanum (14), H. murinum subsp. murinum (7) and subsp. leporinum (35), and the perennial species H. bulbosum (17) and H. secalinum (7). Ten of the tested 64 arbitrary 10-mer primers amplified polymorphic DNA in all taxonomic units. Analyses was performed within and between populations, species and subspecies. The primers gave a total of 250 RAPD products. The level of polymorphism varied between taxonomic units depending on the primers employed and the plant reproductive system. In general, the most variable were the allogamous species H. secalinum and H. bulbosum and the autogamous H. marinum subsp. marinum. Among the amplified bands, 69 (27%) were shared by at least two different taxonomic units. The remaining bands were specific. The results demonstrate differences in the degree of similarity between taxonomic units. Jaccard’s similarity coefficients for interval measure within and between populations were used to produce a cluster diagram using the unweighted pair-group method (UPGMA). The different populations of the species and subspecies of Hordeum fell into three groups. The first group contained the populations belonging to both subspecies of H. marinum, plus those of H. secalinum. The populations of H. marinum subsp. gussoneanum were very closely associated. Those of H. marinum subsp. marinum were grouped in a broad cluster. The second group, occupying the innermost position of the tree, was very closely associated with the populations of both subspecies of H. murinum. The third branch segregated H. bulbosum. A series of RAPD markers were investigated by cleaving the amplified products of the same size with restriction endonucleases that recognize targets of 4- or 6-bp. The production of equivalent fragments following cleavage by the same enzyme would seem to demonstrate their homology in samples from different individuals, populations or taxonomic units. [ABSTRACT FROM AUTHOR]

The lateral posterior-pulvinar (LP-P) complex of mammals receives a major input from the superior colliculus (SC). We have studied the response properties of LP cells and investigated the effects of reversible inactivation of the colliculus on the visual responses of LP units in anesthetized and paralyzed rabbits. Cells in LP had large receptive fields responsive to either stationary or moving stimuli. One third of the motion-sensitive cells were direction selective. The size of the receptive fields increased with eccentricity and there was a retinotopic organization along the dorso-ventral axis. Comparison of the LP and superior colliculus properties revealed substantial differences in visual response characteristics of these two structures such as the size of the receptive fields and the number of direction-selective cells. Electrical stimulation of the LP evoked antidromic action potentials in tectal cells that were motion sensitive. We found a dorsoventral gradient in the projections of collicular cells. Units located more dorsally in the colliculus sent their axons to LP while cells lying more ventrally sent axons toward the region lying posterior to LP. A micropipette filled with lidocaine hydrochloride was lowered into the superficial layers of the superior colliculus in order to reversibly inactivate a small population of collicular cells. Rendering the superior colliculus inactive produced a sharp attenuation of visual responses in the majority of LP cells. Some neurons ceased all stimulus-driven activity after collicular blockade while a few cells exhibited increased excitability following collicular inactivation. These experiments also indicate that the tecto-LP path is topographically organized. An injection in the colliculus failed to influence the thalamic response when it was not in retinotopic register with the LP cells being recorded. Our results demonstrate that the superior colliculus input to LP is mainly excitatory in nature. [ABSTRACT FROM AUTHOR]

This study analyzes the interactions between two discrete stimuli located in the visual field of the rabbit at the lateral geniculate level. Single unit recordings were carried out simultaneously from the superior colliculus (SC) and lateral geniculate nucleus (LGN) in anesthetized and paralyzed rabbits. A first conditioning stimulus (most often a moving target) was positioned in the receptive field of the collicular cell to ensure activation of the retino-collicular path. A second test stimulus was introduced into the receptive field of the LGN cell. The presentation of this latter stimulus was timed so as to fire the geniculate cell at various delays after the collicular neuron had responded to its own stimulus. The spontaneous firing of each cell was unaffected by the stimulus appropriate to the complementary unit. The conditioning collicular stimulus produced increases or decreases in geniculate responses. This modulation may eventually reduce the direction specificity of a geniculate unit. The fluctuations of the geniculate responses peaked 200 to 300 ms after collicular cells had responded. In a separate series of experiments the influence of the conditioning stimulus on geniculate responses was abolished when the SC was locally inactivated. These results suggest that the well documented colliculo-geniculate system mediates the interactions of several stimuli in the visual field. The outcome of this processing results in a modulation of geniculate responses. [ABSTRACT FROM AUTHOR]