A proposed framework for conducting data-based test analysis.

The authors argue that the current state of applied data-based test analytic practice is unstructured and unmethodical due in large part to the fact that there is no clearly specified, widely accepted test analytic framework for judging the performances of particular tests in particular contexts. Drawing from the extant test theory literature, they propose a rationale that may be used in data-based test analysis. The components of the proposed test analytic framework are outlined in detail, as are examples of the framework as applied to commonly encountered test evaluative scenarios. A number of potential extensions of the framework are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Diet preference in rats (Rattus norvegicus) as a function of odor exposure, odor concentration, and conspecific presence.

The relative contributions of social and stimulus factors in development of rat dietary preferences were examined. Investigation of odor-alone effects revealed that weak odors resulted in preference for familiar-odor diets, but only at longer exposure times. Shorter exposure to strong odors also produced differences in diet preference. When odor and conspecific presence were manipulated simultaneously, odors produced no diet preference at low intensities, whereas high-intensity odors did so regardless of conspecific presence. Medium-intensity odor concentrations produced differences only with conspecifics present, indicating social enhancement of stimuli that are ineffective in isolation. These results suggest the separate influence of social and stimulus factors on dietary preferences and explain contradictions in previous studies. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dehydration anorexia in decerebrate rats.

Hypertonic saline (HS) administered intraperitoneal/ly (ip) reduced the intake of sucrose solution infused intraorally in tube-fed decerebrate rats, as it did in control animals. Similarly, either ip or intravenous HS markedly decreased the intake of laboratory chow by neurologically intact control rats. These observations complement recent findings that lesions of putative osmoreceptors in the ventral diencephalon, which eliminate thirst and blunt pituitary secretion of vasopressin and oxytocin in response to HS in rats, have no apparent effect on the HS-induced inhibition of food intake. Taken together they support previous studies indicating an important role for the caudal brainstem in the central control of food intake and suggest that such brainstem control may also include the inhibition of food intake induced by acute hyperosmolality. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Global-local analysis in HIV-1 infection.

One hundred twenty-one HIV-seropositive (HIV+) individuals and 85 seronegative controls performed a divided-attention task that engaged automatic and controlled attentional processing. Reaction times (RTs) to global and local targets that varied in probability were measured in 5 conditions. A neutral condition where global and local targets were equally probable was included as baseline. Participants showed expected tradeoffs in RTs as a function of target-level probability, with longer RTs to less probable targets and shorter RTs to more probable targets. However, the HIV+ group showed significantly greater costs compared with controls. Results are consistent with previous findings that HIV+ individuals are selectively impaired on tasks of controlled attentional processing, particularly under conditions of divided attention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceived stress and caregiver burden after brain injury: A theoretical integration.

Presents a theoretical integration of the literature examining burden among caregivers of brain-injured persons. An examination of various conceptualizations of caregiver burden suggests that the most parsimonious definition for burden is that of perceived stress, or the perception that the caregiving situation exceeds the caregiver's resources with which to cope. Using traditional stress theory as a framework, relationships are suggested between variables identified in the brain injury literature. Particularly, perceived stress might be expected to mediate the effects of other variables identified in the literature. Viewing caregiver burden as a complex process involving a number of variables should aid the understanding of burden and suggest areas for future research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On babies and bathwater: Disease impact and negative affectivity in the self-reports of persons with rheumatoid arthritis.

The degree to which self-reports of health and functioning reflect negative affectivity (NA), a dispositional tendency to emphasize the negative, was examined with data from a 7-year longitudinal study of adaptation to rheumatoid arthritis. Principal component analyses performed on each of 8 waves of data consistently indicated that the dominant factor in these data was defined by measures of pain and functional impairment. In the final wave, Disease Impact, a scale derived from this component, was directly compared to NA. The 2 scales demonstrated considerable discriminant validity, and most of the significant intercorrelations among Disease Impact and the other variables examined remained statistically significant after the influence of NA was partialed out. These results suggest that reports of pain, impairment, and associated variables reflected disease-related outcomes and processes and not simply NA. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Probability effects on stimulus evaluation and response processes.

Investigated the effects of probability information on response preparation and stimulus evaluation. Eight Ss responded with 1 hand to the target letter H and with the other to the target letter S. The target letter was surrounded by noise letters that were either the same as or different from the target letter. In 2 conditions, the targets were preceded by a warning stimulus unrelated to the target letter. In 2 other conditions, a warning letter predicted that the same letter or the opposite letter would appear as the imperative stimulus with .80 probability. Correct reactions times (RTs) were faster and error rates were lower when imperative stimuli confirmed the predictions of the warning stimulus. Probability information affected (1) the preparation of motor responses during the foreperiod, (2) the development of expectancies for a particular target letter, and (3) a process sensitive to the identities of letter stimuli but not to their locations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

ω3 Fatty acids increase spontaneous release of cytosolic components from tumor cells

Mice fed menhaden (fish) oil or coconut oil-rich diets were inoculated intraperitoneally with a rapidly growing leukemia, T27A. After one week, the tumor cells were harvested, and⁵¹Cr was used to label intracellular molecules. Spontaneous release of⁵¹Cr was used as a measure of plasma membrane permeability. Compared to cells from mice fed coconut oil (rich in saturated fatty acids), tumor cells from mice fed menhaden oil (rich in long chain polyunsaturated ω3 fatty acids) showed an increased level of spontaneous⁵¹Cr release, which was exacerbated by increased temperature and reduced by extracellular protein. At physiological salt concentrations, the releated⁵¹Cr was detected in particles of ∼2700 daltons. Enhanced permeability correlated with the incorporation of dietary (fish oil) ω3 polyunsaturated fatty acids docosahexaenoic and eicosapentaenoic acid into the tumor cells. The results demonstrate that ω3 fatty acids are incorporated into cellular constituents of tumor cells and change properties associated with the plasma membrane. This result suggests that dietary manipulation may be used to enhance tumor cell permeability and contribute to tumor eradication.     

TRPV1: A Common Denominator Mediating Antinociceptive and Antiemetic Effects of Cannabinoids

The most common medicinal claims for cannabis are relief from chronic pain, stimulation of appetite, and as an antiemetic. However, the mechanisms by which cannabis reduces pain and prevents nausea and vomiting are not fully understood. Among more than 450 constituents in cannabis, the most abundant cannabinoids are Δ⁹-tetrahydrocannabinol (THC) and cannabidiol (CBD). Cannabinoids either directly or indirectly modulate ion channel function. Transient receptor potential vanilloid 1 (TRPV1) is an ion channel responsible for mediating several modalities of pain, and it is expressed in both the peripheral and the central pain pathways. Activation of TRPV1 in sensory neurons mediates nociception in the ascending pain pathway, while activation of TRPV1 in the central descending pain pathway, which involves the rostral ventral medulla (RVM) and the periaqueductal gray (PAG), mediates antinociception. TRPV1 channels are thought to be implicated in neuropathic/spontaneous pain perception in the setting of impaired descending antinociceptive control. Activation of TRPV1 also can cause the release of calcitonin gene-related peptide (CGRP) and other neuropeptides/neurotransmitters from the peripheral and central nerve terminals, including the vagal nerve terminal innervating the gut that forms central synapses at the nucleus tractus solitarius (NTS). One of the adverse effects of chronic cannabis use is the paradoxical cannabis-induced hyperemesis syndrome (HES), which is becoming more common, perhaps due to the wider availability of cannabis-containing products and the chronic use of products containing higher levels of cannabinoids. Although, the mechanism of HES is unknown, the effective treatment options include hot-water hydrotherapy and the topical application of capsaicin, both activate TRPV1 channels and may involve the vagal-NTS and area postrema (AP) nausea and vomiting pathway. In this review, we will delineate the activation of TRPV1 by cannabinoids and their role in the antinociceptive/nociceptive and antiemetic/emetic effects involving the peripheral, spinal, and supraspinal structures.