Testing effects in mixed- versus pure-list designs.

In the present study, we investigated the role of list composition in the testing effect. Across three experiments, participants learned items through study and initial testing or study and restudy. List composition was manipulated, such that tested and restudied items appeared either intermixed in the same lists (mixed lists) or in separate lists (pure lists).

Mechanical performance of spider orb webs is tuned for high-speed prey.

Spiders in the Orbiculariae spin orb webs that dissipate the mechanical energy of their flying prey, bringing the insects to rest and retaining them long enough for the spider to attack and subdue their meals. Small prey are easily stopped by webs but provide little energetic gain. While larger prey offer substantial nourishment, they are also challenging to capture and can damage the web if they escape.

Spider orb webs rely on radial threads to absorb prey kinetic energy.

The kinetic energy of flying insect prey is a formidable challenge for orb-weaving spiders. These spiders construct two-dimensional, round webs from a combination of stiff, strong radial silk and highly elastic, glue-coated capture spirals. Orb webs must first stop the flight of insect prey and then retain those insects long enough to be subdued by the spiders.

On the validity of remember-know judgments: evidence from think aloud protocols.

The use of remember-know judgments to assess subjective experience associated with memory retrieval, or as measures of recollection and familiarity processes, has been controversial. In the current study we had participants think aloud during study and provide verbal reports at test for remember-know and confidence (i.e.

Testing effects for common versus proper names.

The present study examines the testing effect as a function of item meaningfulness. In Experiments 1 and 2 participants studied lists of words that could serve as proper names or occupations (e.g.

Damping capacity is evolutionarily conserved in the radial silk of orb-weaving spiders.

Orb-weaving spiders depend upon their two-dimensional silk traps to stop insects in mid flight. While the silks used to construct orb webs must be extremely tough to absorb the tremendous kinetic energy of insect prey, webs must also minimize the return of that energy to prey to prevent insects from bouncing out of oscillating webs. We therefore predict that the damping capacity of major ampullate spider silk, which forms the supporting frames and radial threads of orb webs, should be evolutionarily conserved among orb-weaving spiders.

Hydrodynamic pumping by serial gill arrays in the mayfly nymph Centroptilum triangulifer.

Aquatic nymphs of the mayfly Centroptilum triangulifer produce ventilatory flow using a serial array of seven abdominal gill pairs that operates across a Reynolds numbers (Re) range from 2 to 22 during ontogeny. Net flow in small animals is directed ventrally and essentially parallel to the stroke plane (i.e.

Behavioural and biomaterial coevolution in spider orb webs.

Mechanical performance of biological structures, such as tendons, byssal threads, muscles, and spider webs, is determined by a complex interplay between material quality (intrinsic material properties, larger scale morphology) and proximate behaviour. Spider orb webs are a system in which fibrous biomaterials--silks--are arranged in a complex design resulting from stereotypical behavioural patterns, to produce effective energy absorbing traps for flying prey. Orb webs show an impressive range of designs, some effective at capturing tiny insects such as midges, others that can occasionally stop even small birds.

Supercontraction forces in spider dragline silk depend on hydration rate.

Spider dragline silk is a model biological polymer for biomimetic research due to its many desirable and unusual properties. 'Supercontraction' describes the dramatic shrinking of dragline silk fibers when wetted. In restrained silk fibers, supercontraction generates substantial stresses of 40-50 MPa above a critical humidity of approximately 70% relative humidity (RH).

Sleep disturbances associated with posttraumatic stress disorder and alcohol dependence.

Sleep disturbances commonly appear in the context of both posttraumatic stress disorder (PTSD) and alcohol use disorders. Sleep symptoms typically reported among clinical populations include delayed sleep onset, poor sleep continuity, early morning awakening, and disturbed sleep architecture. The aim of the present study was to examine multiple forms of sleep disturbances among individuals with comorbid PTSD and alcohol dependence, PTSD only, alcohol dependence only, and a control group.

Refining estimates of public health spending as measured in national health expenditures accounts: the United States experience.

Providing for the delivery of public health services and understanding the funding mechanisms for these services are topics of great currency in the United States. In 2002, the Department of Homeland Security was created and the responsibility for providing public health services was realigned among federal agencies. State and local public health agencies are under increased financial pressures even as they shoulder more responsibilities as the vital first link in the provision of public health services.

Improved estimates of capital formation in the National Health Expenditure Accounts.

The National Health Expenditure Accounts (NHEA) were revised with the release of the 2004 estimates. The largest revision was the incorporation of a more comprehensive measure of investment in medical sector capital. The revision raised total health expenditures' share of gross domestic product (GDP) from 15.

Health spending growth slows in 2003.

The pace of health spending growth slowed in 2003 for the first time in seven years, driven in part by a slowdown in public spending growth. U.S.

National health expenditures, 2002.

National health expenditures (NHE) were $1.6 trillion in 2002, a 9.3-percent increase from 2001.

Health spending rebound continues in 2002.

U.S. health care spending climbed to dollars 1.

Trends in U.S. health care spending, 2001.

U.S. health care spending grew 8.

Mechanics of cuticular elastic energy storage in leg joints lacking extensor muscles in arachnids.

Certain leg joints in arachnids lack extensor muscles and have elastically deformable transarticular sclerites spanning their arthrodial membranes, an arrangement consistent with a model in which flexor muscles load transarticular sclerites during flexion and energy from elastic recoil is used for extension. This study quantifies the potential contribution of elastic recoil to extension torque at joints of the fourth leg of representative arachnids. Extension torques of isolated joints with and without transarticular sclerites were measured as the joint was rotated through angles and at angular velocities comparable with those used by walking animals.

National health expenditures, 1999.

The health care spending share of gross domestic product (GDP) remained steady between 1993 and 1999 as moderate-to-strong economic growth coincided with a rapid shift to managed care. This shift, along with decelerating growth in Medicare spending, appears to have generated a mostly one-time saving that lowered aggregate health expenditure growth.

National health projections through 2008.

Health spending is expected to resume its rise as a share of gross domestic product (GDP) in the projection period, following 6 years of near stability, increasing from 13.5 percent in 1997 to an estimated 16.2 percent by 2008.

National health expenditures, 1998.

In 1998, national health care expenditures reached $1.1 trillion, an increase of 5.6 percent from the previous year.

National health expenditures, 1997.

In 1997 health spending in the United States increased just 4.8 percent to $1.1 trillion.

Hospital, employment, and price indicators for the health care industry: first quarter 1997.

This regular feature of the journal includes a discussion of recent trends in health care spending, employment, and prices. The statistics presented in this article are valuable in their own right and for understanding the relationship between the health care sector and the overall economy. In addition, they allow us to anticipate the direction and magnitude of health care cost changes prior to the availability of more comprehensive data.