Adjunctive yoga v. health education for persistent major depression: a randomized controlled trial.

BACKGROUND: The objective of this study was to determine whether hatha yoga is an efficacious adjunctive intervention for individuals with continued depressive symptoms despite antidepressant treatment. METHOD: We conducted a randomized controlled trial of weekly yoga classes (n = 63) v. health education classes (Healthy Living Workshop; HLW; n = 59) in individuals with elevated depression symptoms and antidepressant medication use. HLW served as an attention-control group. The intervention period was 10 weeks, with follow-up assessments 3 and 6 months afterwards. The primary outcome was depression symptom severity assessed by blind rater at 10 weeks. Secondary outcomes included depression symptoms over the entire intervention and follow-up periods, social and role functioning, general health perceptions, pain, and physical functioning. RESULTS: At 10 weeks, we did not find a statistically significant difference between groups in depression symptoms (b = -0.82, s.e. = 0.88, p = 0.36). However, over the entire intervention and follow-up period, when controlling for baseline, yoga participants showed lower levels of depression than HLW participants (b = -1.38, s.e. = 0.57, p = 0.02). At 6-month follow-up, 51% of yoga participants demonstrated a response (⩾50% reduction in depression symptoms) compared with 31% of HLW participants (odds ratio = 2.31; p = 0.04). Yoga participants showed significantly better social and role functioning and general health perceptions over time. CONCLUSIONS: Although we did not see a difference in depression symptoms at the end of the intervention period, yoga participants showed fewer depression symptoms over the entire follow-up period. Benefits of yoga may accumulate over time.

The relationships among physical activity, sedentary behaviour, obesity and quitting behaviours within a cohort of smokers in California.

BACKGROUND: Smoking, insufficient physical activity (PA), sedentary behaviour (SB) and obesity are leading risk factors for morbidity and premature mortality. Few studies examining the relationship between these behavioural risk factors and quitting behaviours among cohorts of smokers have been published. PURPOSE: The goals of this study are to examine the cross-sectional relationships among behavioural health risk factors (insufficient PA, SB and obesity) and past year quitting behaviours within a sample of smokers. METHODS: The California Smokers Cohort, conducted from 2011 through 2013, is a population-based survey of adult smokers in California. Using follow-up data (n = 1050), participants' self-reported health behaviours and past year quitting behaviours were examined in univariate analyses and multivariate logistic regression analyses controlling for demographic covariates. RESULTS: In univariate analyses examining health behaviours among smokers, all three health behaviours examined (PA, SB and obesity) were related, and significantly more obese smokers with high PA and low SB reported a ≥20% smoking rate reduction than smokers with other combinations of health behaviours (48.8%, Chi-squared = 4.765, P = 0.045). In multivariate models adjusted for sociodemographic characteristics, obese smokers (odds ratio [OR] = 1.450, 95% confidence interval [CI]: 1.088-1.932, P = 0.011) and smokers with higher levels of PA (OR = 1.448, 95% CI: 1.111-1.887, P = 0.006) were more likely to report a past year ≥24-hour quit attempt regardless of SB, and obese smokers (OR = 1.760, 95% CI: 1.095-2.828, P = 0.019) were more likely to report being quit for ≥30 days regardless of PA and SB. CONCLUSIONS: Overall, the results demonstrated that more physically active and obese smokers were more likely to report positive strides towards quitting. These findings support the potential positive effect of addressing multiple health behaviours along with smoking.

Spatial and temporal genetic structure in a hybrid cordgrass invasion.

Invasive hybrids and their spread dynamics pose unique opportunities to study evolutionary processes. Invasive hybrids of native Spartina foliosa and introduced S. alterniflora have expanded throughout San Francisco Bay intertidal habitats within the past 35 years by deliberate plantation and seeds floating on the tide. Our goals were to assess spatial and temporal scales of genetic structure in Spartina hybrid populations within the context of colonization history. We genotyped adult and seedling Spartina using 17 microsatellite loci and mapped their locations in three populations. All sampled seedlings were hybrids. Bayesian ordination analysis distinguished hybrid populations from parent species, clearly separated the population that originated by plantation from populations that originated naturally by seed and aligned most seedlings within each population. Population genetic structure estimated by analysis of molecular variance was substantial (F(ST)=0.21). Temporal genetic structure among age classes varied highly between populations. At one population, the divergence between adults and 2004 seedlings was low (F(ST)=0.02) whereas at another population this divergence was high (F(ST)=0.26). This latter result was consistent with local recruitment of self-fertilized seed produced by only a few parental plants. We found fine-scale spatial genetic structure at distances less than ∼200 m, further supporting local seed and/or pollen dispersal. We posit a few self-fertile plants dominating local recruitment created substantial spatial genetic structure despite initial long-distance, human dispersal of hybrid Spartina through San Francisco Bay. Fine-scale genetic structure may more strongly develop when local recruits are dominated by the offspring of a few self-fertile plants.

Effects of motivational interviewing on smoking cessation in adolescents with psychiatric disorders.

OBJECTIVE: To test the hypothesis that among adolescent smokers hospitalised for psychiatric and substance use disorders, motivational interviewing (MI) would lead to more and longer quit attempts, reduced smoking, and more abstinence from smoking over a 12 month follow up. DESIGN: Randomised control trial of MI versus brief advice (BA) for smoking cessation, with pre- and post-intervention assessment of self efficacy and intentions to change, and smoking outcome variables assessed at one, three, six, nine, and 12 month follow ups. SETTING: A private, university affiliated psychiatric hospital in Providence, Rhode Island, USA. PATIENTS OR OTHER PARTICIPANTS: Consecutive sample (n = 191) of 13-17 year olds, admitted for psychiatric hospitalisation, who smoked at least one cigarette per week for the past four weeks, had access to a telephone, and did not meet DSM-IV criteria for current psychotic disorder. INTERVENTIONS: MI versus BA. MI consisted of two, 45 minute individual sessions, while BA consisted of 5-10 minutes of advice and information on how to quit smoking. Eligible participants in both conditions were offered an eight week regimen of transdermal nicotine patch upon hospital discharge. MAIN OUTCOME MEASURES: Point prevalence abstinence, quit attempts, changes in smoking rate and longest quit attempt. Proximal outcomes included intent to change smoking behaviour (upon hospital discharge), and self efficacy for smoking cessation. RESULTS: MI did not lead to better smoking outcomes compared to BA. MI was more effective than BA for increasing self efficacy regarding ability to quit smoking. A significant interaction of treatment with baseline intention to quit smoking was also found. MI was more effective than BA for adolescents with little or no intention to change their smoking, but was actually less effective for adolescents with pre-existing intention to cut down or quit smoking. However, the effects on these variables were relatively modest and only moderately related to outcome. Adolescents with comorbid substance use disorders smoked more during follow up while those with anxiety disorders smoked less and were more likely to be abstinent. CONCLUSIONS: The positive effect of MI on self efficacy for quitting and the increase in intention to change in those with initially low levels of intentions suggest the benefits of such an intervention. However, the effects on these variables were relatively modest and only moderately related to outcome. The lack of overall effect of MI on smoking cessation outcomes suggests the need to further enhance and intensify this type of treatment approach for adolescent smokers with psychiatric comorbidity.

Origin and genetic diversity of Spartina anglica (Poaceae) using nuclear DNA markers.

Spartina alterniflora, introduced into the UK in the 1800s, was the seed parent in an interspecific hybridization with S. maritima. The sterile F1 hybrid S. ×townsendii gave rise to the fertile allopolyploid S. anglica by chromosomal doubling. Previous chromosome, isozyme, and cpDNA surveys did not reveal notable genetic variation within either the parental or the hybrid species. We used nuclear DNA markers (random amplified polymorphic DNA ([RAPD]) and inter-simple sequence repeats (ISSR) to further explore the origin, diversity, and parentage of S. anglica. We found DNA fragments in S. ×townsendii were the aggregate of diagnostic DNA fragments from S. maritima and S. alterniflora, thus confirming its hybrid origin. The S. ×townsendii genotype was identical to most of the S. anglica individuals analyzed, establishing the genetic concordance of these two taxa. We found widespread genetic variation within S. anglica. This could indicate that S. anglica arose several times, from different S. maritima sires. Alternatively, alleles could have been lost through recombination and/or through loss of entire chromosomes in S. anglica. Finally, all but one S. anglica individual had a S. alterniflora component that was indistinguishable from a S. alterniflora plant extant in Marchwood, UK, leaving open the possibility that this plant is the actual seed parent of S. anglica.

A taxometric analysis of MMPI-2 Infrequency scales [F and F(p)] in clinical settings.

The typology of overreporting, which is a deliberate attempt to amplify symptoms, simulate psychopathology, or understate coping capacities, was examined using taxometric procedures with Minnesota Multiphasic Personality Inventory-2 (MMPI-2) Infrequency scales [F and F(p)] in psychiatric inpatient and Veterans Affairs (VA) medical center treatment settings. Overreporting was identified as a taxon using several taxometric procedures, and the multiple estimates of the taxon base rate were consistent within each sample. Mean base-rate estimates were .27 and .19 for the psychiatric inpatient and VA medical center settings, respectively. Overall classification rates ranged from .80 to .97 across the 2 settings, which supports the use of F and F(p) in the identification of overreporting on the MMPI-2 in psychiatric inpatient and VA medical center settings.

Ecology. Biological control of invading species--risk and reform.

Conservation relies increasingly on biological control (BC) of organisms that invade in natural and agricultural areas throughout the world. However, some BC organisms have harmed native species. In the United States, regulations are based on old laws meant to bar agricultural pests, and these are particularly ineffective in protecting native invertebrate animals. Improved ecological safety of BC depends on recognizing that BC is not appropriate for every pest, factoring ecological safety into the selection of BC agents, and limiting the importation and dissemination of agents that can harm either native animals or plants. Reasonable reform of BC will insure the viability of this valuable tool for both agriculture and conservation.

Reciprocal hybrid formation of Spartina in San Francisco Bay.

Diversity in the tRNALEU1 intron of the chloroplast genome of Spartina was used to study hybridization of native California cordgrass, Spartina foliosa, with S. alterniflora, introduced to San Francisco Bay approximately 25 years ago. We sequenced 544 bases of the tRNALEU1 intron and found three polymorphic sites, a pyrimidine transition at site 126 and transversions at sites 382 and 430. Spartina from outside of San Francisco Bay, where hybridization between these species is impossible, gave cpDNA genotypes of the parental species. S. foliosa had a single chloroplast haplotype, CCT, and this was unique to California cordgrass. S. alterniflora from the native range along the Atlantic coast of North America had three chloroplast haplotypes, CAT, TAA, and TAT. Hybrids were discriminated by random amplified polymorphic DNA (RAPD) phenotypes developed in a previous study. We found one hybrid that contained a cpDNA haplotype unknown in either parental species (TCT). The most significant finding was that hybridization proceeds in both directions, assuming maternal inheritance of cpDNA; 26 of the 36 hybrid Spartina plants from San Francisco Bay contained the S. foliosa haplotype, nine contained haplotypes of the invading S. alterniflora, and one had the cpDNA of unknown origin. Furthermore, cpDNA of both parental species was distributed throughout the broad range of RAPD phenotypes, suggesting ongoing contributions to the hybrid swarm from both. The preponderance of S. foliosa cpDNA has entered the hybrid swarm indirectly, we propose, from F1s that backcross to S. foliosa. Flowering of the native precedes by several weeks that of the invading species, with little overlap between the two. Thus, F1 hybrids would be rare and sired by the last S. foliosa pollen upon the first S. alterniflora stigmas. The native species produces little pollen and this has low viability. An intermediate flowering time of hybrids as well as pollen that is more vigourous and abundant than that of the native species would predispose F1s to high fitness in a vast sea of native ovules. Thus, spread of hybrids to other S. foliosa marshes could be an even greater threat to the native species than introductions of alien S. alterniflora.

Taxometric analysis of impression management and self-deception on the MMPI-2 in child-custody litigants.

The typology of impression management (IM), a deliberate attempt to create a positive social image, and self-deceptive positivity (SDP), an unintentional concealment of symptoms, were examined using taxometric procedures with MMPI-2 (Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989) underreporting scales in several custody-litigant samples. IM was identified as a taxon using several procedures and estimates of the base rate that were consistent (.40, .37, .31, .36, .37). SDP was better characterized as a dimensional construct. Means and estimated validities for MMPI-2 underreporting scales in this sample are reported. IM and SDP appear to be distinct and measurable underreporting constructs on the MMPI-2.

Evolution of a new ecotype of Spartina alterniflora (Poaceae) in San Francisco Bay, California, USA.

We report the discovery and spread of a dwarf ecotype of Spartina alterniflora in San Francisco Bay. Relative to typical S. alterniflora, this dwarf ecotype has one-fifth the tiller height (∼21 cm), tenfold the tiller density (∼4000 tillers/m(2)), and is restricted to growth in the upper intertidal zone. Chromosome counts of the dwarfs are identical to typical smooth cordgrass (2n = 62), and smooth cordgrass-specific random amplified DNA markers confirm the species identity of the dwarf. Field-collected clonal fragments of the dwarf grown for 2 yr under high-nutrient conditions maintained the dwarf syndrome, as did plants grown from the seed of a dwarf. The dwarf condition is not caused by endophytic fungi. The first dwarf smooth cordgrass patch was discovered in 1991, and by 1996 five separate dwarf patches had appeared within 200 m of the original. Since 1991, total area covered by the dwarf ecotype has increased sixfold to 140 m(2). The ecological range of the dwarf smooth cordgrass ecotype is similar to that of S. patens, a competitor on the Atlantic coast. We suggest that the absence of S. patens from most of San Francisco Bay has allowed the dwarf ecotype of smooth cordgrass to survive and spread.

Greater male fitness of a rare invader (Spartina alterniflora, Poaceae) threatens a common native (Spartina foliosa) with hybridization.

Hybridization with abundant invaders is a well-known threat to rare native species. Our study addresses mechanisms of hybridization between a rare invader, smooth cordgrass (Spartina alterniflora) and the common native California cordgrass (S. foliosa) in the salt marshes of San Francisco Bay. These species are wind-pollinated and flower in summer. The invader produced 21-fold the viable pollen of the native, and 28% of invader pollen germinated on native stigmas (1.5-fold the rate of the native's own pollen). Invader pollen increased the seed set of native plants almost eightfold over that produced with native pollen, while native pollen failed to increase seed set of the invader. This pollen swamping and superior siring ability by the invader could lead to serial genetic assimilation of a very large native population. Unlike California cordgrass, smooth cordgrass can grow into low intertidal habitats and cover open mud necessary to foraging shorebirds, marine life, navigation, and flood control in channels. To the extent that intertidal range of the hybrids is more similar to the invader than to the native parent, introgression will lead to habitat loss for shore birds and marine life as well to genetic pollution of native California cordgrass.

Effect of nematode-trapping fungi on an entomopathogenic nematode originating from the same field site in California.

We determined whether nematode-trapping fungi may influence the dynamics of a coastal shrub community. The food chain interactions in the shrub community involve the dominant plant species, its major insect herbivore, and an entomopathogenic nematode, Heterorhabditis hepialus. Of the 12 nematode-trapping fungi previously isolated from soils at the study site, 5 were selected for this study. Arthrobotrys oligospora, Geniculifera paucispora, Monacrosporium eudermatum, and Monacrosporium cionopagum efficiently trapped and colonized H. hepialus on agar; in contrast Nematoctonus concurrens trapped but did not infect or colonize the nematode on agar. To determine whether these fungi can suppress H. hepialus in soil, we added the fungi in the form of fungal-colonized nematodes to pasteurized (2 hr at 62 degrees C) and raw (nontreated) soil from the study site. Suppression was measured by comparing nematode invasion into a wax moth larva in fungus-treated and untreated soil in vials at 20 degrees C. Fungal population density in soil was estimated using dilution plating and most probable number procedures. All fungi suppressed H. hepialus if the wax moth larvae were added 4 days after the nematodes. Suppression ranged between 37 and 54% and did not differ among fungi. Suppression was usually greater in raw than in pasteurized soil. Raw soil contained a constant background of nematode-trapping fungi, and A. oligospora was the most common among these; no background was detected in pasteurized soil. The presence of background fungi in raw soil may explain the higher suppression in raw than in pasteurized soil. Fungal propagule densities in our laboratory experiments were similar to those observed in the field, suggesting that nematode-trapping fungi may influence the dynamics of the plant, insect herbivore, and entomopathogenic nematode in the coastal ecosystem.

A disjunct Californian strain of Entomophaga aulicae infecting Orgyia vetusta.

Fungal epizootics occurred in abundant Orgyia vetusta (western tussock moth; Lepidoptera: Lymantriidae) populations on Lupinus arboreus bushes growing on the Pacific coast north of San Francisco, California. The causative pathogen was isolated and identified as Entomophaga aulicae, Group II, based on RFLPs using rDNA and PCR-amplified rDNA products. Inability of this fungus to infect the lymantriid Lymantria dispar (gypsy moth) confirmed its distinction from Entomophaga maimaiga, the only other member of this species complex which predominantly infects lymantriids. Later instar wandering by O. vetusta in outbreak populations and close proximity of larvae in dense populations are characteristics most probably promoting development of E. aulicae epizootics; these life history patterns are also typical of Lymantria dispar populations experiencing epizootics of E. maimaiga.

Response of xylem-feeding leafhopper to host plant species and plant quality.

Carneocephala floridana, an oligophagous leafhopper that inhabits the salt marshes along the coasts of Florida, utilizesBorrichia frutescens andSalicornia virginica (both herbs) as primary summer hosts, but uses two grasses,Distichlis spicata andSpartina alterniflora, during the winter. We tested whether the seasonal patterns of abundance and apparent host-switching byCarneocephala are related to plant quality. In laboratory experiments, nymphs ofCarneocephala reared on nonfertilized control plants of the two herbs produced adults that were similar in size to field-collected insects. OnlyCarneocephala raised at the lowest densities onSpartina andDistichlis from the highest fertilizer treatments produced adults similar in body mass to those reared on nonfertilizedBorrichia andSalicornia. ForDistichlis, superior quality (high foliar nitrogen) plants were able to mitigate the negative effect of nymphal crowding on adult body mass. However, laboratory fertilization regimes produced an extremely high foliar nitrogen content in the two herbs and the organic acid concentration in the xylem fluid ofBorrichia, the only host species suitable for xylem fluid extraction, increased 2.5- to 3-fold. Total amino acid concentration in the xylem fluid of fertilizedBorrichia decreased compared to nonfertilized plants.Carneocephala demonstrated reduced feeding efficiencies on high nitrogenBorrichia. Our results suggest thatCarneocephala prefers, and performs better on, plants with high nitrogen content up to a threshold, beyond which high nitrogen levels result in reduced leafhopper feeding rates and assimilation efficiencies.

Entomopathogenic nematodes: natural enemies of root-feeding caterpillars on bush lupine.

A new species of soil-dwelling entomopathogenic nematode Heterorhabditis hepialus killed up to 100% (mean=72%) of root-boring caterpillars of a ghost moth Hepialus californicus in coastal shrub lands. When unchecked, ghost moth caterpillars killed bush lupine, Lupinus arboreus. Here we describe this strange food chain. Although unappreciated by ecologists, entomopathogenic nematodes are widespread and probably one of the most important groups of natural enemies for underground insects. The free-living infective juvenile (IJ) of entomopathogenic nematodes searches for host insects in the soil. A single IJ can kill a host, although several often invade together. After entering the host through a spiracle or other orifice, the IJ regurgitates its symbiotic bacterium, Photorhabdus luminescens, which kills the host within 48 h. The bacteria digest the cadaver and provide food for the exponentially growing nematode population inside. The bacteria produce antibiotics and other noxious substances that protect the host cadaver from other microbes in the soil. When the cadaver is exhausted of resources, IJs break the host integument and can disperse. As many as 420,000 IJs can be produced within a large ghost moth caterpillar. Surface soil of the lupine rhizosphere is the primary habitat of IJs of H. hepialus. Attracted to waste gases emitted by insects, the 0.5-mm-long IJs can move 6 cm/day through moist soil. Prevalences of H. hepialus ranged from as high as 78% of rhizospheres in some lupine stands to almost zero in others, but it was absent from no stand at our study site. Field intensities ranged from 0.003 IJs/cm3 of soil to 7.5 IJs/cm3, and correlated roughly with prevalences among sites. Few ghost moth caterpillars (mean=6.7) succeeded in entering lupine roots where prevalence of H. hepialus was highest, and this stand had lowest mortality (0.02) of mature bush lupine. In the three stands with lowest prevalence (mean = 2%) of this nematode, many caterpillars (mean = 38.5) entered roots, and lupine mortality was high (range = 0.41-1.0). Old aerial photographs indicate that the stands with highest recent nematode prevalence have had little or no mass die-off of lupine over the past 40 years. The photos depict repeated die-offs of lupine during the past four decades in stands with lowest recent prevalence of the nematode. This pattern leads us to entertain the hypothesis that the nematode affects vegetation dynamics indirectly through a trophic cascade. Dispersal of entomopathogenic nematodes is little understood. We found that air drying of soil extirpates H. hepialus and speculate that this nematode is dispersed during the wet season in moist soil bits on the exterior of fossorial insects and mammals. H. hepialus colonized some previously unoccupied lupine rhizospheres during the wet winter-spring season and, obversely, became extinct from some rhizosperes as soil dried in summer. Root-feeding insects have only recently been recognized as a force in communities, and the regulation of these important herbivores is still largely an ecological terra incognita. All evidence indicates that entomopathogenic nematodes are found throughout terrestril ecosystems, and we propose that trophic chains similar to those described in this report should not be uncommon.