Microbes frequently live in nature as small, densely packed aggregates containing ∼10(1)-10(5) cells. These aggregates not only display distinct phenotypes, including resistance to antibiotics, but also, serve as building blocks for larger biofilm communities. Aggregates within these larger communities display nonrandom spatial organization, and recent evidence indicates that this spatial organ...

Two groups of aggregates with fractal dimensions of 1.81 ( 0.09 and 2.33 ( 0.07 were generated by coagulation of latex microspheres (2.84 μm) in a Jar-test (paddle-mixing) device. The collision rates between these fractal aggregates (200-1000 μm) and small (1.48 μm) particles were measured for individual aggregates that had settled through a suspension of the small particles. Aggregate permeabi...

Sedimentation of red blood cell aggregates was experimentally investigated by optical imaging. Suspensions of red blood cell at low hematocrit were obtained from blood of healthy donors. The velocity of three-dimensional red blood cell aggregates was measured using particle image velocimetry. The magnitude and spatial correlation functions of the velocity fluctuations of the settling aggregates...

This paper defines new constructs to support aggregation in the temporal query language TQuel and presents their formal semantics in the tuple relational calculus. A formal semantics for Que1 aggregates is defined in the process. Multiple aggregates; aggregates appearing in the where, when, and valid clauses; nested aggregation; and instantaneous, cumulative, moving window, and unique variants ...

A cell culture platform for neuron aggregates has been designed and fabricated as an in vitro model for studying CNS myelination. The device is composed of nine culture chambers each of which has 55 cell trapping sites for culturing neuron aggregates in a spatially controlled environments in parallel. Neuron aggregates prepared from embryonic day 16 rat fetus were cultured with oligodendrocyte ...

In this paper we present a comparison of two approaches for storing and processing of long aggregates lists in a spatial data warehouse. An aggregates list contains aggregates, calculated from the data stored in the database. Our comparative criteria are: the efficiency of retrieving the aggregates and the consumed memory. The first approach assumes using a modified Java list supported with mat...

Incubation of mouse peritoneal macrophages with native human low density lipoprotein (LDL) did not cause any significant storage of intracellular cholesteryl esters. However, when the LDL was subjected to brief (30-second) vortexing, it formed self-aggregates that were rapidly ingested and degraded by macrophages, converting them to cholesteryl ester-rich foam cells. Such aggregates were as pot...

Embryonic stem (ES) cells form spontaneous aggregates during differentiation, and cell-cell communication in the aggregates plays an important role in differentiation. The development of a controlled differentiation scheme for ES cells has been hindered by the lack of a reliable method to produce uniform aggregate sizes. Conventional techniques, such as hanging drop and suspension cultures, do ...

In the world's oceans, even relatively low oxygen levels inhibit anaerobic nitrogen cycling by free-living microbes. Sinking organic aggregates, however, might provide oxygen-depleted microbial hotspots in otherwise oxygenated surface waters. Here, we show that sinking diatom aggregates can host anaerobic nitrogen cycling at ambient oxygen levels well above the hypoxic threshold. Aggregates wer...