Search

Harmful algal blooms (HABs) are common in many eutrophic lakes and frequently associated with nutrient excesses, warm waters, and calm conditions. While HABs can also occur in oligotrophic waterbodies, bloom‐stimulating factors remain elusive for these ecosystems. Here, using a high‐frequency sensor platform supported by hydrodynamic modeling, we document a clearly linked sequence of three hydrodynamic events that immediately preceded each HAB event on Skaneateles Lake, NY during 2018. HABs were first preceded by interactions between internal waves in the thermal structure of the lake with the northern slope of the lakebed. These interactions disturbed sediments resulting in upwelling of nutrient‐rich sediment and possibly cyanobacterial cells into the lower water column. Next, moderate winds stimulated Langmuir circulation which facilitated the transport of material from the lower water column to well‐lit surface waters. Finally, the sequence culminated with a calm wind period, which is often classically associated with surface HAB formation. While individual steps in this sequence occurred independently and repeatedly throughout the year, the complete sequence occurred only eight times, immediately preceding each of the eight documented HABs. We empirically derive thresholds for and timing of the sequence to independently predict HAB occurrence and elevated cyanobacteria levels in the lake. The discovery of this specific and repeated event sequence and the identified thresholds provides the potential for forecasting of HABs days in advance. Ongoing climate change impacts, including increasing water column thermal stratification and changing wind speeds may alter the frequency, timing, and duration of this sequence and consequent HAB formation. [ABSTRACT FROM AUTHOR]

This essay contests the standard historical comparison that links Husserl's account of time-consciousness to the tradition by way of Book XI of Augustine's Confessions. This comparison rests on the mistaken assumption that both thinkers attribute the soul's distention and corresponding apprehension of time to memory. While true for Augustine and Husserl's 1905 lectures on time, Husserl concluded after 1907 that these lectures advanced the flawed and counter-intuitive position that memory extends perception. I will trace the shortcomings of Augustine's and Husserl's conflation of memory with perception. After developing Husserl's maturely articulated distinction between memory and retention from 1911, I suggest chapters 10-14 of Aristotle's Physics IV as a more apt anticipation of this second, more adequate half of the Husserlian story. A reconstruction of Aristotle's definition of time as 'the number of movement,' one that privileges the activity of 'the mind pronouncing that the 'nows' are two,' intimates Husserl's distinction between memory and retention. For Aristotle, the soul's recognition of the 'nows' as two depends not on memory, but on the soul's intentional activity of counting, itself dependent on the ability to, as Aristotle writes in his Metaphysics, 'grasp mentally and [have] already grasped' at the same time.

RICOEUR, Paul. Memory, History, Forgetting. Translated by Kathleen Blamey and David Pellauer. Chicago: University of Chicago Press, 2004. xvii + 642 pp. Cloth, $ 40.00--The last English translation to appear [...]