Growth-regulating characteristics of trinexapac-ethyl, paclobutrazol, and flurprimidol were investigated on ‘Tifway’ bermudagrass and four turfgrass weeds (large crabgrass, goosegrass, bahiagrass, and purple nutsedge). All treatments reduced the height of Tifway bermudagrass (25 to 37%) and large crabgrass (14 to 34%), but the height of purple nutsedge, goosegrass, and bahiagrass was not consistently changed. In 1995, all rates of trinexapac-ethyl reduced clipping weights of Tifway bermudagrass (70 to 87%) and bahiagrass (53 to 59%) more than large crabgrass, goosegrass, or purple nutsedge (< 39%). Trinexapac-ethyl (0.4 kg ai/ha) and paclobutrazol (1.1 kg ai/ha) applications increased both large crabgrass clipping weight and canopy visible density. Increased large crabgrass density was attributed to greater tiller numbers with trinexapac-ethyl (60 tillers/pot) and paclobutrazol (63 tillers/pot) compared to untreated large crabgrass plants (53 tillers/pot). Weed growth was not suppressed as much as Tifway bermudagrass growth; therefore, turfgrass stands may be adversely affected by plant growth regulator use under weedy conditions.

Kyllinga species are becoming more prevalent in turfgrass sites throughout North America. The effects of nitrate (50, 200, and 400 mg L−1), temperature (33/24, 25/17, 19/11 C day/night, respectively), and light on seed germination of three Kyllinga species were investigated in growth chambers. Nitrate concentrations did not stimulate Kyllinga species seed germination compared with untreated seeds. All Kyllinga species seeds failed to germinate in darkness but resumed germination once they were placed in light. This is an important pest management strategy because a dense, uniform turfgrass stand with its minimum light penetration to the soil would minimize Kyllinga species seed germination. Higher temperatures increased seed germination rate and percentage of each species after 8 wk. Maximal (> 90%) K. brevifolia germination occurred 2 to 4 wk after initiation in every seed study, whereas K. squamulata seeds germinated continuously. Minimal (< 10%) K. pumila seeds germinated until alternating diurnal temperatures were imposed.

Kyllinga species are becoming more common throughout the southeastern United States. Two species, Kyllinga brevifolia and Kyllinga squamulata, in particular are prevalent weeds in turfgrass. To better understand these weeds, growth chamber studies determined the growth of K. brevifolia, K. squamulata, and Cynodon dactylon × Cynodon transvaalensis as influenced by three temperature regimes (33/24, 25/17, 19/11 C day/night, respectively). Temperature influenced almost all aspects of Kyllinga species growth. Plant height of both Kyllinga species increased nearly twofold after 8 wk at high temperatures. Plants were mowed each week to 2.5 cm; both species produced more than twice as many clippings by 8 wk at high (33/24 C) temperatures than at low (19/11 C) temperatures. Destructive analysis at 8 wk revealed that K. brevifolia shoot and root weight increased with decreasing temperature, whereas K. squamulata shoot and root weights were not affected by temperature. Shoot weight percentage for both Kyllinga species increased from 59% in medium temperatures to 69% in high temperatures. K. brevifolia shoot weight percentage decreased to 53% in low temperatures, whereas K. squamulata shoot weight percentage increased to 72%. K. brevifolia inflorescences formed at 2, 3, and 5 wk in high, medium, and low temperatures, respectively, whereas K. squamulata flowered immediately in all temperatures. C. dactylon × C. transvaalensis and Kyllinga species growth were similar within each temperature regime throughout the 8-wk study.

Holocene deposits of Mahoney Lake, a meromictic saline lake located in a closed basin in the semi-arid Okanagan Valley, contain evidence of frequent and marked changes in lake depth (up to >12 m/10014C yr) probably caused by short-term changes in effective precipitation. We studied a 5.45-m-long core comprising a basal layer of inorganic mud overlain by a succession of layers of calcareous laminated and nonlaminated organic mud, marl, and sand. We used Mazama tephra to adjust nine radiocarbon ages for the hardwater effect. Meromixis developed ca. 900014C yr B.P., and the lake has been episodically meromictic for about half the time since. Because of close linkages between sediments and depositional environments in meromictic and saline lakes, we infer that laminated sediments indicate meromictic conditions and high lake levels (>ca. 12 m water depth), whereas thick marl layers and nonlaminated sediments indicate nonmeromictic conditions and thus low lake levels (<ca. 8 m depth). Many of the inferred short-term climatic changes have not been identified in previous studies in northwestern North America, perhaps because of insensitive climatic proxies, inadequate temporal resolution, or discounting of anomalous findings.

A field study evaluated the effects of green kyllinga establishment method (seed vs. stolon), two mowing heights (2.5 and 5.0 cm), and three nitrogen (N) rates (0, 24, and 49 kg/ha/mo) on green kyllinga infestation in ‘Tifway’ bermudagrass turf. The study was initiated in vigorous and newly established or “weak” bermudagrass turf in May 1997 and continued until December 1998. The green kyllinga area was measured periodically each year and plant dry weight (g/500 cm2) was calculated in December 1997 and 1998. In 1997, stolon established green kyllinga plots were twice as large as seeded plots in vigorous turf and four times larger in weak turf. Method of establishment, however, was less important in 1998 as seedling populations became more established. In weak turf, increasing N rate to 49 kg/ha/mo decreased green kyllinga spread by 50% in 1997 and by 40% in 1998 compared to no N. In vigorous turf, mowing height influenced green kyllinga infestation more than N. Low mowing height (2.5 cm) increased green kyllinga infestations nearly twofold in vigorous turf in 1997 and more than fivefold in 1998. Golf course fairways are often maintained at clipping heights shorter than 2.5 cm, and green kyllinga is a prevalent weed at these sites. Green kyllinga may gain a competitive advantage in bermudagrass turf at lower mowing heights.

A 4-yr field study was conducted to evaluate yellow nutsedge suppression in ‘Tifway’ bermudagrass. Herbicide programs included preemergence (PRE) applications of metolachlor (3.4 kg ai/ha) and postemergence (POST) applications of imazaquin (0.28 kg ai/ha) plus MSMA (2.2 kg ai/ha) or halosulfuron (0.07 kg ai/ha) plus MSMA (2.2 kg/ha). Herbicides were applied to the same plots each year. Yellow nutsedge shoot suppression and tuber numbers were determined each year. Suppression of yellow nutsedge shoots increased over the 4-yr period from <74% in 1993 to >83% by 1996 with two annual applications of imazaquin plus MSMA or halosulfuron plus MSMA. PRE metolachlor applications did not suppress shoot production in any year; nor did they enhance suppression from POST treatments. Sequential applications of halosulfuron plus MSMA and imazaquin plus MSMA increased shoot suppression by 17 to 24% at 3 mo after initial treatment (MAIT) compared to single applications. All treatments reduced tuber numbers (>60%) after 4 years compared to untreated plots.

The microprobe-determined glass shard major element chemistry of tephras derived from five North Island, New Zealand volcanoes (Mayor Island, Okataina, Taupo, Tongariro, and Mount Egmont) and younger than ca. 20,000 yr B.P. was subjected to discriminant function analysis. Four separate approaches were adopted to test the match of the tephras with their known sources: (1) an analysis of raw microprobe data; (2) an analysis of normalized data; (3) an analysis of the data transformed by calculating the log10 of oxide scores divided (arbitrarily) by the chlorine content; and (4) a repeat of (3) with multivariate outlier scores, as determined by principal components analysis, deleted. All yielded excellent classification functions (efficiencies of 91–100%), with the eruptives associated with each of the five volcanoes being chemically distinct from one another. In each approach, the first two canonical discriminant functions accounted for >90% of the variation between groups. The removal of multivariate outliers from the data set had only minor effects on the performance of the discriminant function procedures. Separate discriminant function analysis of the relatively alike Taupo and Okataina eruptives gave a greater degree of multivariate separation. The numerical classifications generated should enable unidentified tephras erupted since ca. 20,000 yr B.P. from the five volcanoes to be provisionally matched with their sources.

The pattern of climate change in the Southern Hemisphere during the Younger Dryas (YD) chronozone provides essential constraint on mechanisms of abrupt climate change only if accurate, high-precision chronologies are obtained. A climate reversal reported previously at Kaipo bog, New Zealand, had been dated between 13,600 and 12,600 cal yr B.P. and appeared to asynchronously overlap the YD chron, but the chronology, based on conventionally radiocarbon-dated bulk sediment samples, left the precise timing questionable. We report a new high-resolution AMS 14C chronology for the Kaipo record that confirms the original chronology and provides further evidence for a mid-latitude Southern Ocean cooling event dated between 13,800 and 12,400 cal yr B.P. (2σ range), roughly equivalent to the Antarctic Cold Reversal.

Kyllinga squamulata has become problematic in bermudagrass turf in recent years, probably related to shifts in herbicide use strategies. Preemergence and postemergence greenhouse and field herbicide studies evaluated K. squamulata control in bermudagrass turf. Excellent (≥90%) postemergence control at 6 wk after initial treatment (WAIT) followed single and sequential applications of imazaquin at 0.42 kg ai/ha, MSMA plus imazaquin at 1.12 + 0.42 kg ai/ha, and sulfentrazone at 0.56 kg ai/ha. In one of two experiments, unacceptable (>30%) bermudagrass injury occurred with imazaquin at 0.42 and 0.56 kg ai/ha and MSMA plus imazaquin at 1.12 + 0.42 kg ai/ha 1 wk after application; however, plots recovered fully by 2 wk. In the field at 18 WAIT, preemergence control of greater than 70% was obtained with a single application of oxadiazon at 1.12 or 2.24 kg ai/ha and sequential applications of 1.12 kg ai/ha each 8 wk apart. Sequential applications 8 wk apart of sulfentrazone at 0.28 followed by 0.28 kg/ha also provided greater than 70% preemergence control. In two greenhouse studies, oxadiazon at 2.24 kg/ha and sulfentrazone at 0.56 kg/ha provided greater than 90% preemergence control.

Objectives: Connectionist theories of brain function took hold with the seminal contributions of Norman Geschwind a half century ago. Modern neuroimaging techniques have expanded the scientific interest in the study of brain connectivity to include the intact as well as disordered brain. Methods: In this review, we describe the most common techniques used to measure functional and structural connectivity, including resting state functional MRI, diffusion MRI, and electroencephalography and magnetoencephalography coherence. We also review the most common analytical approaches used for examining brain interconnectivity associated with these various imaging methods. Results: This review presents a critical analysis of the assumptions, as well as methodological limitations, of each imaging and analysis approach. Conclusions: The overall goal of this review is to provide the reader with an introduction to evaluating the scientific methods underlying investigations that probe the human connectome. (JINS, 2016, 22, 105–119)

The present research examined the perceptions of Australian employees on dimensions of workplace stress. The sample included 664 male (n = 234) and female (n = 430) workers from the public (n = 559) and private (n = 105) sectors. Participants completed the Health and Safety Executive Indicator Tool as a measure of workplace stress. Results indicated that private sector employees rated their employers as being more effective in managing workplace stress, while employees in both sectors rated their employers as less effective in managing Job Content stressors than Job Context stressors. Compared with normative benchmarks, employees overall also reported risks of stress associated with Relationships and Role. Implications of these findings and suggestions for future research were discussed.

To examine how task demands influence bilingual advantage in executive control over monolinguals, we tested 32 Chinese monolinguals and 32 Chinese–English bilinguals with four versions of a color-shape switching task. During switching trials, the task required participants to suppress one set of conflicting (or non-conflicting) responses and simultaneously to activate another set of conflicting (or non-conflicting) responses. The results showed that compared to monolinguals, (i) when suppressing conflicting responses or (ii) activating non-conflicting responses, bilinguals had significantly smaller switching costs though similar mixing costs; (iii) when suppressing one set of conflicting responses and simultaneously activating another set of conflicting responses, bilinguals had significantly smaller switching costs though larger mixing costs; and (iv) when suppressing one set of non-conflicting responses and simultaneously activating another set of non-conflicting responses, bilinguals had similar switching costs and mixing costs. These findings indicate that task demands affect bilingual advantage in executive control.