Bellisotoma, a new genus of Isotomidae from North America (Hexapoda, Collembola).

A new genus of Isotomidae, Bellisotoma gen. n., is described. The new genus is a member of the Proisotoma genus complex and is characterized by a combination of having a bidentate mucro with wide dorsal lamellae that join clearly before the end of mucronal axis without forming a tooth and one strong ventral rib with basal notch that articulates with dens; having abundant chaetotaxy on both faces of dens; and abundant tergal sensilla. Bellisotoma gen. n. shows a furcula adapted to a neustonic mode of life, and may be a Isotopenola-like derivative adapted to neustonic habitats. Subisotoma joycei Soto-Adames & Giordano, 2011 and Ballistura ewingi James, 1933 are transferred to the new genus.

Correlates of pre-treatment drop-out among persons with marijuana dependence.

AIMS: Our objective was to identify client characteristics and other factors associated with pre-treatment drop-out by people with marijuana dependence. DESIGN AND PARTICIPANTS: Data from the Marijuana Treatment Project's screening assessment were used to examine correlates of pre-treatment drop-out. Information from all eligible study participants (n = 813) (i.e. those who were interested in receiving treatment for their marijuana dependence and were determined to be eligible for the randomized treatment efficacy trial) was used to examine differences between the 450 participants who initiated treatment (by enrolling in the trial) and the 363 individuals who declined enrollment. SETTING: The study was conducted at three community-based outpatient treatment facilities in Farmington, CT, Seattle, WA and Miami, FL. MEASUREMENTS: The information gathered in the screening interview included demographic characteristics, residential stability variables, employment and education history and referral source. Substance use variables included the number of days and the number of times per day marijuana was used, self-perceived dependence on marijuana, alcohol or other drugs, other drug use history and current treatment (i.e. substance abuse, medical, psychiatric) situation. FINDINGS: Stepwise logistic regression was conducted to confirm variables associated with treatment initiation in bivariate analyses. Pre-treatment drop-out was associated with being younger, unmarried, unemployed, less educated and Asian American or Native American. It was also associated with self-perceived dependence on marijuana and use of other drugs. CONCLUSIONS: By recognizing demographic and substance use factors that may serve as barriers for individuals accessing treatment for marijuana dependence, clinicians may target clients with these characteristics proactively to encourage treatment initiation and subsequent attendance.

Cognitive functioning of long-term heavy cannabis users seeking treatment.

CONTEXT: Cognitive impairments are associated with long-term cannabis use, but the parameters of use that contribute to impairments and the nature and endurance of cognitive dysfunction remain uncertain. OBJECTIVE: To examine the effects of duration of cannabis use on specific areas of cognitive functioning among users seeking treatment for cannabis dependence. DESIGN, SETTING, AND PARTICIPANTS: Multisite retrospective cross-sectional neuropsychological study conducted in the United States (Seattle, Wash; Farmington, Conn; and Miami, Fla) between 1997 and 2000 among 102 near-daily cannabis users (51 long-term users: mean, 23.9 years of use; 51 shorter-term users: mean, 10.2 years of use) compared with 33 nonuser controls. MAIN OUTCOME MEASURES: Measures from 9 standard neuropsychological tests that assessed attention, memory, and executive functioning, and were administered prior to entry to a treatment program and following a median 17-hour abstinence. RESULTS: Long-term cannabis users performed significantly less well than shorter-term users and controls on tests of memory and attention. On the Rey Auditory Verbal Learning Test, long-term users recalled significantly fewer words than either shorter-term users (P =.001) or controls (P =.005); there was no difference between shorter-term users and controls. Long-term users showed impaired learning (P =.007), retention (P =.003), and retrieval (P =.002) compared with controls. Both user groups performed poorly on a time estimation task (P<.001 vs controls). Performance measures often correlated significantly with the duration of cannabis use, being worse with increasing years of use, but were unrelated to withdrawal symptoms and persisted after controlling for recent cannabis use and other drug use. CONCLUSIONS: These results confirm that long-term heavy cannabis users show impairments in memory and attention that endure beyond the period of intoxication and worsen with increasing years of regular cannabis use.