Spatio-temporal dynamics of ichthyoplankton in the Kowie estuary, South Africa

Ichthyoplankton dynamics in the permanently open Kowie Estuary, in the warm temperate region of South Africa was investigated. The composition, abundance, distribution and seasonality of larval fishes were studied over a two year period between 2004 and 2006. Additionally, tidal exchange of ichthyoplankton and the use of frontal zones in the mouth region of the estuary were also explored between 2008 and 2009. Temporal and spatial trends in occurrence of larval fishes within the estuary and associated marina were obtained from data collected seasonally using boat-based plankton netting at 14 sampling stations along the length of the estuary. A total of 11 128 larval fishes were collected, representing 23 families and 38 taxa. Clupeidae and Gobiidae were the dominant fish families, contributing 47.0 % and 24.7 % respectively to the total catch. Estuarine resident species dominated the overall catch (91 %). A notable absence of older stage larvae and early juveniles characterised the artificial channels of the marina and estuary mouth region. This was attributed to the absence of a shallow, marginal water habitat typical of successful estuarine nursery areas. Tidal exchange of larval fishes was investigated in the Kowie Estuary using a new technique. A set of drifting light traps were set repetitively on the ebb and flood tide every second night for two consecutive 14 day periods during the peak estuarine recruitment period. A total of 553 larval fishes were caught during the study, representing nine families and 26 species. Blenniidae and Clupeidae dominated the catches. Family and species occurrence changed with tide state. Species richness (d) and diversity (H’) varied with tide and was highest on flood tides. Estuary-dependent species, such as Omobranchus woodii were more dominant on flood tides, whilst larvae of marine-spawned species, such as Sardinops sagax, were dominant on the ebb tide. Light trap catches yielded a different composition in terms of development stage / size and species, when compared to towed net studies. Towed plankton nets were again used to study the shear fronts that characterise the mouth region of the canalised Kowie Estuary. It was hypothesised that the convergence zone of the front provides feeding opportunities for ichthyoplankton. Ichthyoplankton, zooplankton and phytoplankton was collected from within and immediately outside of the convergence zone during frontal conditions. Species specific distribution trends emerged from this study. Postflexion larvae and early juvenile stages of the estuary dependent Mugilidae were only present in the foam line of the convergence zones. Some known predators of ichthyoplankton were also present in slightly higher numbers in the convergence zone (isopods) while other predators such as mysid shrimps, chaetognaths and cnidarians were more abundant out of the convergence zone. It appears that these zones may provide access to temporary food patches in the lower estuary but will be accompanied by a trade-off with increased isopod predators. The Kowie Estuary is a heavily impacted system and lack of adequate freshwater supply; artificial channelling and pollution ultimately have a negative impact of the success of this system as a nursery area. Rehabilitation of marginal areas in the lower estuary and marina is suggested as remedial action to re-establish the integrity of the nursery function this system could offer

Physiological Arousal during Couple Financial Discussions as a Precursor to Seeking Financial Planning Help

There continues to be a great need for financial guidance within American households, yet the utilization of professional financial help, despite its growing accessibility, is low. It has been suggested that physiological arousal is an important factor that influences help-seeking behaviors. This paper tests the hypothesis that help-seeking intentions at the couple level are shaped in part by physiological arousal within the couple. Although exploratory, findings suggest the greater the joint level of arousal, the more likely a couple will be to report an intention to meet with a financial planner. Couples who experience a higher level of arousal during a financial therapy session were found to be more likely to self-report an intention to engage in future financial planning services. Conversely, couples who reported less intention to seek help responded with less arousal during sessions. Implications for financial professionals working with couples are discussed

Perceptions of a Partner\u27s Spending and Saving Behavior and Financial Satisfaction

The purpose of this study was multifaceted. The first purpose was to test a relatively new scale—the Spender-Saver Perception Scale (Kruger, 2019)—to determine if perceptions of one’s marriage or cohabitation partner’s spending and saving behavior can be used to describe the subjective financial satisfaction of the one making the appraisal. The second purpose was to determine in an exploratory manner whether perceptions of spending and saving differ by the gender of someone in a marital or committed cohabitating relationship. Data for the study were obtained from an online survey of 313 adults. Partner perceptions were evaluated using a scale developed by Kruger (2019), whereas financial satisfaction was measured using a 10-point subjective self-evaluation item. Respondents were categorized into one of three spender and saver groups: (1) those who perceived their partner as a spender, (2) those who perceived their partner as a saver, and (3) those who perceived their partner somewhere between a spender and saver. It was determined that perceiving one’s marital or cohabitating partner as a spender was not associated with the financial satisfaction. However, perceiving one’s partner as a saver was found to be positively associated with financial satisfaction for the person making the assessment

Preference of aphids (Hemiptera : Aphididae) for lucerne, maize, soybean and wheat and their potential as prospective border crops for Potato virus Y management in seed potatoes

Aphid landing rates, species composition and abundance on lucerne (Medicago sativa), maize (Zea mays), soybean (Glycine max), wheat (Triticum aestivum) and potato (Solanum tuberosum) were determined in a small-scale field trial to identify potential crops as prospective border plants for seed potatoes to reduce the spread of Potato virus Y (PVY) in South Africa. Aphids were sampled using green bucket traps to estimate aphid landing rates, whereas leaf counts and sweep-netting were used to identify colonizing species. Of the 34 species or species groups collected with green bucket traps, 18 were previously known vectors of PVY. The most abundant vector species or species groups were Acyrthosiphon pisum, Macrosiphum euphorbiae, Metopolophium dirhodum, Myzus persicae, Rhopalosiphum padi and Sitobion spp. The only other species that occurred in high numbers, but whose vector status is unknown, were Acyrthosiphon kondoi and Tetraneura fusiformis. Landing patterns suggest that A. kondoi, A. pisum and M. dirhodum may be able to discriminate between plant species and select their preferred host plant, if available within a habitat patch, in the pre-alighting phase, whereas other species such as R. padi seemed less selective. Results on aphid landing together with colonization of the crops evaluated suggest that maize and wheat show the highest potential as possible crop border plants in regions where aphids colonizing Poaceae, and lucerne in regions where aphids colonizing Fabaceae are abundant. Soybean appears to be less suitable because cultivars with a high trichome density, which reduces colonization by aphids, are preferentially planted in South Africa.Potatoes South Africa (PSA), the University of Pretoria and a grant from the Technology and Human Resources for Industry Programme (THRIP) of the National Research Foundation of South Africa. (TP2005101300009). The research was undertaken as part of M.L. Fourie’s (Schröder) M.Sc. degree."http://www.journals.co.za/ej/ejour_ento.html2016-03-30am201

Health Behavior Risk Factors Across Age as Predictors of Cardiovascular Disease Diagnosis

Objectives: The current study examines the prevalence of health risk behaviors and their cumulative effects on cardiovascular disease (CVD) among a sample of adults. Age cohort is also examined to determine the role of age in predicting CVD and risky health behaviors. Method: Medical records of a sample of adults from the Seattle Longitudinal Study categorized into one of four age-group cohorts were examined. Data regarding participants' health risk behaviors were examined individually and cumulatively for predicting later CVD diagnosis. Results: The prevalence of CVD increases with age, obesity, and risky medical checkups. Female risky sleepers are more likely to receive a CVD diagnosis than men who report risky sleep patterns (p < .05). Discussion: A high risk of CVD appears to exist for adults across the life span, and several risky health behaviors also seem to place individuals more at risk for being diagnosed with CVD

Critical research needs for successful food systems adaptation to climate change

There is a growing sense of the fragility of agricultural production in the Global North and South and of increasing risks to food security, as scientific observations confirm significant changes in the Gulf Stream, polar ice, atmospheric CO2, methane release, and other measures of climate change. This sense is heightened as each of us experiences extreme weather, such as the increasing frequency of droughts, floods, unseasonal temperatures, and erratic seasonality. The central research challenge before us is how global, national, regional, and local food systems may adapt to accelerating climate change stresses and uncertainties to ensure the availability, access, consumption, and stability of healthy food for and by all people. Missing aspects of research fall into two broad categories: the impacts of rapid climate change on the environmental systems supporting food production, and climate change’s impact on the predominantly human systems that influence food security. Of particular concern is how different policy and governance mechanisms can support or hinder the collective decision-making needed to promote a swift adaptive response to increase and sustain food security. Human systems research is needed to investigate food system activities beyond production (processing, distribution, consumption, and waste management). It also must consider political, cultural, and regulatory factors that influence behavior and facilitate positive behavioral changes. To accurately envision future scenarios, research is needed to characterize risk comprehensively throughout the food system, assess barriers to and opportunities for changing food systems, and evaluate novel and traditional approaches that may lead to greater food security

Factors associated with bone mineral density and bone resorption markers in postmenopausal hiv-infected women on antiretroviral therapy: A prospective cohort study

The study aimed to determine factors associated with changes in bone mineral density (BMD) and bone resorption markers over two years in black postmenopausal women living with human immunodeficiency virus (HIV) on antiretroviral therapy (ART). Women (n = 120) aged > 45 years were recruited from Potchefstroom, South Africa. Total lumbar spine and left femoral neck (LFN) BMD were measured with dual energy X-ray absorptiometry. Fasting serum C-Telopeptide of Type I collagen (CTx), vitamin D and parathyroid hormone were measured. Vitamin D insufficiency levels increased from 23% at baseline to 39% at follow up. In mixed linear models serum CTx showed no change from baseline to end (p = 0.363, effect size = 0.09). Total and LFN BMD increased significantly over two years, but effect sizes were small. No significant change in spine BMD over time was detected (p = 0.19, effect size = 0.02). Age was significantly positively associated with CTx over time, and negatively with total and LFN BMD. Physical activity (PA) was positively associated with LFN BMD (p = 0.008). Despite a decrease in serum vitamin D, BMD and CTx showed small or no changes over 2 years. Future studies should investigate PA interventions to maintain BMD in women living with HIV

Visual cues and host-plant preference of the bird cherry-oat aphid, Rhopalosiphum padi (Hemiptera: Aphididae)

Alate aphids respond to short (UV) and long (green-yellow) wavelength stimuli during host-plant searching behaviour. Although many aphids are attracted to yellow, the bird cherry-oat aphid, Rhopalosiphum padi, is attracted to green. As part of identifying suitable plant species for crop border plants for seed potatoes, the attraction of R. padi to different shades of green in relation to differences in spectral reflectance of three cultivars of a non-host, potato, and two host-plant species, maize and wheat, were determined. Choice experiments were carried out under laboratory conditions to evaluate aphid landing preference for stimuli of different colours. Rhopalosiphum padi alates preferred to land on the colour targets with the highest reflectance. Significantly more alates landed on yellow and lime colour targets with a maximum wavelength reflectance of 46 % from 600-610 nm and 26 % from 525-531 nm, respectively. The peak light reflectance of the crop plants ranged between 12 % (potato; 532-555 nm) and 20 % (wheat; 537-553 nm). The results on aphid landing preference for different colour targets suggest that R. padi will land in higher numbers on the wheat plants, compared to potato, due to their higher peak percentage reflectance. In addition, the study indicates that the wavelength reflectance curves of plants can be used as a characteristic to select possible crop border plants when making choices between seemingly equally suitable plant species/cultivars.Potatoes South Africa (PSA), the Technology and Human Resources for Industry Programme (THRIP), the National Research Foundation (NRF) and the University of Pretoria.http://www.journals.co.za/ej/ejour_ento.html2016-07-30am201

Olfactory responses of Rhopalosiphum padi to three maize, potato, and wheat cultivars and the selection of prospective crop border plants

Understanding host plant volatile – aphid interactions can facilitate the selection of crop border plants as a strategy to reduce plant virus incidence in crops. Crop border plant species with attractive odours could be used to attract aphids into the border crop and away from the main crop. As different cultivars of the same crop can vary in their olfactory attractiveness to aphids, selecting an attractive cultivar as a border crop is important to increase aphid landing rates. This study evaluated olfactory responses of the bird cherry-oat aphid, Rhopalosiphum padi (L.) (Hemiptera: Aphididae), to three cultivars each of maize [Zea mays L. (Poaceae)], potato [Solanum tuberosum L. (Solanaceae)], and wheat [Triticumaestivum L. (Poaceae)] with the aim of selecting an attractive crop border plant to reduce the incidence of the non-persistent Potato virus Y [PVY (Potyviridae)] in seed potatoes. Volatiles emitted by the crop cultivars were collected and identified using coupled gas chromatography/ mass spectrometry. Quantitative and qualitative differences were found among cultivars. Behavioural responses of alate R. padi to odours of the cultivars and synthetic compounds identified from the plants were determined with a four-arm olfactometer. Rhopalosiphum padi was attracted to odours emitted from maize cultivar 6Q-121, but did not respond to odours from the remaining eight crop cultivars. Volatile compounds from maize and wheat cultivars that elicited a behavioural response from R. padi and contributed to differences in plant volatile profiles included (Z)-3-hexenyl acetate (attractant) and a-farnesene, (E)-2-hexenal, indole, and (3E,7E)-4,8, 12-trimethyltrideca-1,3,7,11-tetraene (TMTT) (repellents). We conclude that maize cv. 6Q-121 is potentially suitable as a crop border plant based on the behavioural response of R. padi to the olfactory cues emitted by this cultivar. The findings provide insight into selecting crop cultivars capable of attracting R. padi to crop border plants.National Research Foundation (NRF), the University of Pretoria and the Swedish Foundation for Strategic Environmental Research (MISTRA) through the Plant-ComMistra programme. MISTRA and Carl Tryggers Stiftelse.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1570-74582016-11-30hb201