The unity and diversity of executive functions and their contributions to complex "Frontal Lobe" tasks: a latent variable analysis.

Co-Planar Stereotaxic Atlas of the Human Brain—3-Dimensional Proportional System: An Approach to Cerebral Imaging, J. Talairach, P. Tournoux. Georg Thieme Verlag, New York (1988), 122 pp., 130 figs. DM 268

Freshwater biodiversity is the over-riding conservation priority during the International Decade for Action - 'Water for Life' - 2005 to 2015. Fresh water makes up only 0.01% of the World's water and approximately 0.8% of the Earth's surface, yet this tiny fraction of global water supports at least 100000 species out of approximately 1.8 million - almost 6% of all described species. Inland waters and freshwater biodiversity constitute a valuable natural resource, in economic, cultural, aesthetic, scientific and educational terms. Their conservation and management are critical to the interests of all humans, nations and governments. Yet this precious heritage is in crisis. Fresh waters are experiencing declines in biodiversity far greater than those in the most affected terrestrial ecosystems, and if trends in human demands for water remain unaltered and species losses continue at current rates, the opportunity to conserve much of the remaining biodiversity in fresh water will vanish before the 'Water for Life' decade ends in 2015. Why is this so, and what is being done about it? This article explores the special features of freshwater habitats and the biodiversity they support that makes them especially vulnerable to human activities. We document threats to global freshwater biodiversity under five headings: overexploitation; water pollution; flow modification; destruction or degradation of habitat; and invasion by exotic species. Their combined and interacting influences have resulted in population declines and range reduction of freshwater biodiversity worldwide. Conservation of biodiversity is complicated by the landscape position of rivers and wetlands as 'receivers' of land-use effluents, and the problems posed by endemism and thus non-substitutability. In addition, in many parts of the world, fresh water is subject to severe competition among multiple human stakeholders. Protection of freshwater biodiversity is perhaps the ultimate conservation challenge because it is influenced by the upstream drainage network, the surrounding land, the riparian zone, and - in the case of migrating aquatic fauna - downstream reaches. Such prerequisites are hardly ever met. Immediate action is needed where opportunities exist to set aside intact lake and river ecosystems within large protected areas. For most of the global land surface, trade-offs between conservation of freshwater biodiversity and human use of ecosystem goods and services are necessary. We advocate continuing attempts to check species loss but, in many situations, urge adoption of a compromise position of management for biodiversity conservation, ecosystem functioning and resilience, and human livelihoods in order to provide a viable long-term basis for freshwater conservation. Recognition of this need will require adoption of a new paradigm for biodiversity protection and freshwater ecosystem management - one that has been appropriately termed 'reconciliation ecology'.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/96AA265E3D88C95FB802E7A73CCB4332/S1464793105006950a.pdf/div-class-title-freshwater-biodiversity-importance-threats-status-and-conservation-challenges-div.pdf

Freshwater biodiversity: importance, threats, status and conservation challenges

Part I. Experimental Studies: 2. Experiment in psychology 3. Experiments on perceiving III Experiments on imaging 4-8. Experiments on remembering: (a) The method of description (b) The method of repeated reproduction (c) The method of picture writing (d) The method of serial reproduction (e) The method of serial reproduction picture material 9. Perceiving, recognizing, remembering 10. A theory of remembering 11. Images and their functions 12. Meaning Part II. Remembering as a Study in Social Psychology: 13. Social psychology 14. Social psychology and the matter of recall 15. Social psychology and the manner of recall 16. Conventionalism 17. The notion of a collective unconscious 18. The basis of social recall 19. A summary and some conclusions.

Remembering. A Study in Experimental and Social Psychology, Cambridge (University Press) 1964.

http://download.neurosky.com/docs/papers/bcq/Klimesch_1999_EEG_alpha_and_theta_oscillations_reflect_cognitive_and_memory_performance.pdf

EEG alpha and theta oscillations reflect cognitive and memory performance: a review and analysis

A guide to sampling freshwater mussel populations

Three experiments were undertaken to measure and understand cognitive distraction while driving. The experiments involved participants performing different mental tasks including: listening to the radio or a book on tape; conversing with a passenger; using a hand-held or hands-free cell phone; using a speech-to-text based email system; or using an auditory version of the Operation Span (OSPAN) task. In the first (control) experiment, participants performed tasks while seated at a computer monitor to establish the cognitive workload of each task. The second experiment involved a driving simulator with a lead vehicle. Brake reaction time and following distance were measured during the performance of the tasks. In the third experiment, participants drove an instrumented vehicle in a residential area while performing the tasks. High definition cameras were used to record eye movement data at critical locations, such as, pedestrian crosswalks, two- and four-way stops, and stoplights. Data was used to create a rating system for cognitive distraction with listening to the radio at 1.21 and using a speech-to-text system at 3.06. The data suggests that the introduction of voice-based systems may increase driver distraction.

/pdf/measuring-cognitive-distraction-in-the-automobile-11p5r5sj06.pdf

Measuring Cognitive Distraction in the Automobile

This study examined the effects of memory search and related processes on both time and frequency domain components of electroencephalographic activity More specifically, we were interested in the relationship between EEG and event-related potential (ERP) components as a function of memory load and response type Subjects performed a semantic memory search task in which they matched word probes to category labels Consistent with previous studies, reaction time increased and accuracy decreased with increasing memory loads A negative component of the ERP (N400) was found to reflect semantic mismatch: N400s were larger for the nontargets than for the targets Two ERP components were found to be reciprocally related to memory load P300 decreased and Negative Slow Wave increased in amplitude with increases in the size of the memory set These two ERP components were reflected by different components in a Principal Components Analysis The power in the theta band (5-7 Hz) also increased as a function of memory load and appears to be functionally and topographically related to the Negative Slow Wave in the ERP It is argued that both measures are jointly determined and reflect the difficulty of the conceptual operations during memory search

Event related potentials and EEG components in a semantic memory search task.

[1] Discharge is a master variable that controls many processes in stream ecosystems. However, there is uncertainty of which discharges are most important for driving particular ecological processes and thus how flow regime may influence entire stream ecosystems. Here the analytical method of effective discharge from fluvial geomorphology is used to analyze the interaction between frequency and magnitude of discharge events that drive organic matter transport, algal growth, nutrient retention, macroinvertebrate disturbance, and habitat availability. We quantify the ecological effective discharge using a synthesis of previously published studies and modeling from a range of study sites. An analytical expression is then developed for a particular case of ecological effective discharge and is used to explore how effective discharge varies within variable hydrologic regimes. Our results suggest that a range of discharges is important for different ecological processes in an individual stream. Discharges are not equally important; instead, effective discharge values exist that correspond to near modal flows and moderate floods for the variable sets examined. We suggest four types of ecological response to discharge variability: discharge as a transport mechanism, regulator of habitat, process modulator, and disturbance. Effective discharge analysis will perform well when there is a unique, essentially instantaneous relationship between discharge and an ecological process and poorly when effects of discharge are delayed or confounded by legacy effects. Despite some limitations the conceptual and analytical utility of the effective discharge analysis allows exploring general questions about how hydrologic variability influences various ecological processes in streams.

/pdf/effective-discharge-analysis-of-ecological-processes-in-1emf47cee9.pdf

Effective discharge analysis of ecological processes in streams

Despite predictions that the zebra mussel (Dreissena polymorpha) invasion of North America would damage fisheries, analyses of actual effects on fish have been few and equivocal. We analyze 26 years of data on fish popula- tions in the Hudson River to quantify changes associated with the zebra mussel invasion. Based on our measurements of changes in the lower food web, we predicted that populations of open-water fish species (e.g., Alosa spp.) would suffer and populations of littoral fish species (e.g., Centrarchidae) would prosper from the zebra mussel invasion. We found that the median decrease in abundance of open-water species was 28%, whereas the median increase in abun- dance of littoral species was 97%. Populations of open-water species shifted downriver away from the zebra mussel population, whereas those of littoral species shifted upriver. Median apparent growth rates fell by 17% among open- water species and rose by 12% in the single littoral species studied. Many of the observed changes were large and in- volved species of commercial or recreational importance (e.g., American shad (Alosa sapidissima), black basses (Micropterus spp.)). The influence of zebra mussels on fish should vary widely across ecosystems as a function of system morphology, factors that limit primary production, and diets of the fish species. Resume : Malgre les predictions voulant que l'invasion des moules zebrees (Dreissena polymorpha) en Amerique du Nord soit nefaste pour les peches, les analyses d'effets reels sont rares et equivoques. Nos analysons 26 annees de don- nees sur les populations de poissons du fleuve Hudson pour quantifier les changements associes a l'invasion des mou- les zebrees. D'apres notre evaluation des modifications de la partie inferieure du reseau alimentaire, nous avions predit que les populations de poissons d'eau libre (e.g., Alosa spp.) seraient defavorisees et que les populations littorales (e.g., les Centrarchidae) seraient avantagees par l'invasion des moules zebrees. Le declin median de l'abondance des especes d'eau libre est de 28 %, alors que l'accroissement median de l'abondance des especes littorales est de 97 %. Les populations d'especes d'eau libre se sont deplacees vers l'aval loin de la population de moules zebrees, alors que celles des especes littorales ont remonte vers l'amont. Les taux medians apparents de croissance ont chute de 17 % chez les especes d'eau libre et augmente de 12 % chez la seule espece littorale etudiee. Plusieurs des changements ob- serves sont considerables et impliquent des especes d'importance commerciale ou sportive (e.g., l'alose savoureuse (Alosa sapidissima), les achigans (Micropterus spp.)). Les effets des moules zebrees sur les poissons devraient varier beaucoup dans les ecosystemes en fonction de la morphologie des systemes, des facteurs limitants de la production pri- maire et du regime alimentaire des especes de poissons.

/pdf/effects-of-an-invasive-bivalve-dreissena-polymorpha-on-fish-5afmxmv2h0.pdf

David L. Strayer

Papers

A guide to sampling freshwater mussel populations

Measuring Cognitive Distraction in the Automobile

Event related potentials and EEG components in a semantic memory search task.

Effective discharge analysis of ecological processes in streams

Effects of an invasive bivalve (Dreissena polymorpha) on fish in the Hudson River estuary