787 research outputs found
Forest edges benefit adults, but not seedlings, of the mistletoe Alepis flavida (Loranthaceae)
1   We tested the hypothesis that different life-history stages of the same plant species show different responses to forest edge and interior environments. We investigated the effects of forest edges on growth, survival and density of seedlings, juveniles and adults of an endemic New Zealand mistletoe, Alepis flavida , over a 5-year period. 2   Rates of establishment and growth were significantly higher for seedlings in forest interior than on forest edges but both juveniles and adults grew significantly faster on forest edges. 3   Mortality rates were greater for juveniles than for adults, but there was no significant difference between forest edge and interior. 4   Densities of seedlings and the larger size class of juvenile plants were significantly greater in the forest interior than on forest edges, whereas densities of the larger size class of adults were significantly greater on edges. 5   Changes in densities over 5 years showed that larger juveniles increased in density only in the forest interior, whereas larger adults increased in density only on forest edges. 6   Thus, seedlings of A. flavida have strong advantages in the forest interior, whereas juveniles and adults grow faster on forest edges. 7   This study emphasizes the need to examine multiple life-history stages in studies of edge effects. Journal of Ecology (2004) doi: 10.1111/j.1365-2745.2004.00961.xPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72224/1/j.1365-2745.2004.00961.x.pd
A Review of Structural MRI and Diffusion Tensor Imaging in Schizotypal Personality Disorder
Individuals with schizotypal personality disorder (SPD) share genetic, phenomenologic, and cognitive abnormalities with people diagnosed with schizophrenia. To date, 15 structural MRI studies of the brain have examined size, and 3 diffusion tensor imaging studies have examined white matter connectivity in SPD. Overall, both types of structural neuroimaging modalities have shown temporal lobe abnormalities similar to those observed in schizophrenia, while frontal lobe regions appear to show more sparing. This intriguing pattern suggests that frontal lobe sparing may suppress psychosis, which is consistent with the idea of a possible neuroprotective factor. In this paper, we review these 18 studies and discuss whether individuals with SPD who both resemble and differ from schizophrenia patients in their phenomenology, share some or all of the structural brain imaging characteristics of schizophrenia. We attempt to group the MRI abnormalities in SPD into three patterns: 1) a spectrum of severity—abnormalities are similar to those observed in schizophrenia but not so severe; 2) a spectrum of region—abnormalities affecting some, but not all, brain regions affected in schizophrenia; and 3) a spectrum of compensation—abnormalities reflecting greater-than-normal white matter volume, possibly serving as a buffer or compensatory mechanism protecting the individual with SPD from the frank psychosis observed in schizophrenia
A COMPARATIVE STUDY OF THE DEFENSE SYNDROMES OF SOME NEW ZEALAND MARINE CRUSTACEA
Five sympatric species of intertidal decapod crustaceans were studied in the field and laboratory with regard to the mechanisms used for predator defense. The species are sympatric and represent a gradient from high intertidal ( Cyclograpsus lavauxi ) to subtidal ( Notomithrax ursus ) with Petrolisthes elongatus , Heterozius rotundifrons , and Halicarcinus innominatus intermediate in tidal distribution. We tested the hypothesis that the diversity of defensive features would increase along a tidal gradient from high to low tide. All species were scored in the field for degree of background matching in color and tendency to autotomize appendages. In the laboratory individuals were scored with regard to delay to first movement following disturbance, maximum speed of movement, maximum extent of cheliped extension, and responses to conspecific alarm odors. Maximum sizes for individuals of the different species were obtained from the published literature. The five species varied significantly in the scores recorded for all of the different defensive features. Halicarcinus innominatus matched its background significantly better, Petrolisthes elongatus autotomized the most readily, Heterozius rotundifrons showed the longest periods of immobility following disturbance, Cyclograpsus lavauxi could move the fastest, and Notomithrax ursus reached the largest size. However, all species utilized multiple mechanisms related to predator avoidance. Summation of the rank scores for the seven different features revealed that the magnitude of the overall diversity of defensive features (1) did not vary along the tidal gradient and (2) showed surprisingly little variation among the different species. ___TAGSTART___BR___TAGEND___Cinq espèces sympatriques de crustacés décapodes intertidaux ont été étudiées sur le terrain et au laboratoire quant aux mécanismes utilisés pour la défense contre les prédateurs. Les espèces sont sympatriques et représentent un gradient de l'intertidal supérieur ( Cyclograpsus lavauxi ) au subtidal ( Notomithrax ursus ) avec Petrolisthes elongatus, Heterozius rotundifrons et Halicarcinus innominatus intermédiaire dans la répartition tidale. Nous avons testé l'hypothèse que la diversité des traits défensifs augmenterait suivant un gradient tidal, de la haute à la basse mer. Toutes les espèces étaient notées sur le terrain sur leur capacité à s'adapter à la couleur du milieu et la tendance à autotomiser des appendices. En laboratoire, les individus ont été notés sur le délai jusqu'au premier mouvement suivant la perturbation, la vitesse maximale du mouvement, l'extension maximale du chélipède, et les réponses aux odeurs d'alarmes spécifiques. Les tailles maximales des individus des différentes espèces ont été obtenues à partir des données publiées. Les cinq espèces différaient de façon significative dans les notes obtenues pour tous les traits de défense. Halicarcinus innominatus s'adapte le mieux au fond, de façon significative, Petrolisthes elongatus s'autotomise le plus facilement, Heterozius rotundifrons a montré les plus longues périodes d'immobilité après une perturbation, Cyclograpsus lavauxi se déplace le plus vite, et Notomithrax ursus a atteint la plus grande taille. Cependant, toutes les espèces ont utilisé des mécanismes multiples pour éviter les prédateurs. La somme des notes relatives aux sept différents critères ont révélé que l'échelle de diversité totale des critères de défense (1) ne variait pas suivant le gradient tidal et (2) montrait une variation étonnamment faible entre les différentes espèces.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43663/1/10613_2004_Article_brill_0011216x_v73n8_s1.pd
Longitudinal Assessment of Gray and White Matter in Chronic Schizophrenia: A Combined Diffusion-Tensor and Structural Magnetic Resonance Imaging Study
Previous studies have reported continued focal gray matter loss after the clinical onset of schizophrenia. Longitudinal assessments in chronic illness, of white matter in particular, have been less conclusive
Normative Alethic Pluralism
Some philosophers have argued that truth is a norm of judgement and have provided a variety of formulations of this general thesis. In this paper, I shall side with these philosophers and assume that truth is a norm of judgement. What I am primarily interested in here are two core questions concerning the judgement-truth norm: (i) what are the normative relationships between truth and judgement? And (ii) do these relationships vary or are they constant? I argue for a pluralist picture—what I call Normative Alethic Pluralism (NAP)—according to which (i) there is more than one correct judgement-truth norm and (ii) the normative relationships between truth and judgement vary in relation to the subject matter of the judgement. By means of a comparative analysis of disagreement in three areas of the evaluative domain—refined aesthetics, basic taste and morality—I show that there is an important variability in the normative significance of disagreement—I call this the variability conjecture. By presenting a variation of Lynch’s scope problem for alethic monism, I argue that a monistic approach to the normative function of truth is unable to vindicate the conjecture. I then argue that normative alethic pluralism provides us with a promising model to account for it
Non-visual functions of crustacean eyestalk ganglia
Ablation experiments demonstrated that in several crustacean groups, the proximal eyestalk ganglia are important in a variety of behavior patterns: 1. Chemical elicitation of feeding via the antennules is altered in lobsters, hermit crabs, and some brachyuran crabs by bilateral eyestalk ablation; the ablation of one antennule and the contralateral eyestalk is effective in lobsters and hermit crabs;Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47106/1/359_2005_Article_BF01245153.pd
Cognitive and mood functioning in borderline and schizotypal personality disorders
Research suggests many shared clinical features across individuals with Schizotypal Personality Disorder (SPD) and Borderline Personality Disorder (BPD), including problems with attention/ executive functioning and mood. Therefore, aspects of these areas of functioning were compared in SPD and BPD to better characterize their respective difficulties. BPD, SPD, and healthy control (HC) participants were administered measures of cognitive and mood functioning. Compared with healthy controls, SPD patients performed significantly worse on aspects of the Delayed-Matching- to-Sample task, a measure of short-term visual memory abilities; however, the individuals with BPD did not differ from healthy controls. Neither of the patient groups differed from HC’s on measures of processing speed or planning. With regard to mood functioning, the BPD group exhibited significantly higher levels of affective disturbance (e.g., sadness, fear, anger) compared with the SPD patients and HCs. Overall, findings suggest different patterns of fronto-subcortical weakness in each patient group. While SPD patients exhibited relative weakness with short-term memory, BPD patient performance on such measures did not reveal relative weakness compared with HCs but did implicate problems with mood
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Developments in synchrotron x-ray microtomography for application to flow in porous media
Microimaging capabilities at Brookhaven National Laboratory`s National Synchrotron Light Source have been enhanced to provide larger and higher resolution 3-D renderings of pore networks in reservoir rocks at a fraction of the time required in previous first Generation scanning methods. Computer Microtomography, CMT, volumes containing 16 million voxels have been acquired at 3 micron resolution with the aid of expansion optics in a matter of hours. Such data are used to model single and multiphase flow properties in digital images of real porous media. Advances in 3-D visualization, which are being implemented in Brookhaven National Laboratory`s 3-D theater, will allow even greater digestion and interpretation of phenomena dependent upon pore interconnectivity and multipore interactions. Pore networks are analyzed for tortuosity and connectivity measures, which have been elusive parameters in transport property models. We present examples of porosimetry simulation via network modeling to produce initial water saturation and residual oil distributions in a water-wet pore system. Furthermore, pore networks can provide the boundary condition framework for more rigorous simulations of displacement, such as in the lattice Boltzmann simulated water flood example provided
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