Higher Flow Levels Research Articles

Electoral Violence and Arms Proliferation in Nigeria: Causes, Consequences and Way Forward

One of the greatest challenges facing governance and political systems in Africa is the violence that ensues whenever elections are conducted. The main objective of the study was to examine the relationship between electoral violence and arms proliferation in Nigeria. It also examines the causes and implications of electoral violence on the electorate, entire community and Nigeria’s political system. The adopted research methodology is desktop research, where information was obtained from journals, textbooks, conference papers and others. The findings of the study revealed a link between small arms and electoral violence, and it was discovered that illicit proliferation of small arms is a major cause of electoral violence in Nigeria. The study established the lack of trust of the politicians on the electoral process which is a challenge to the nation’s nascent democracy and sustainability of peace and security. The study therefore, recommended that security agencies that are involved in the electoral system should be trained on electoral security system, in order to improve the level of security in the country. The study also posits that the control of small arms is very essential in curtailing the high level of illicit flow of arms in the country before and during elections.

Building knowledge stock and facilitating knowledge flow through human resource management practices toward firm innovation

The present study theoretically identifies the meaningful human resource management (HRM) practices that explain the emergence of two distinct dimensions of firm‐level knowledge management, namely, firm knowledge stock and flow, which are critical drivers of firm innovation. We also propose that these knowledge dimensions interact synergistically and that their effects on firm innovation are accentuated in firms with strong innovation strategy. The proposed theoretical framework was tested using multisource, large‐scale data collected from 203 manufacturing companies at three time points over a 5‐year period. Analysis confirmed that stock‐building and flow‐facilitating HRM practices increase firm‐level knowledge stock and flow, respectively. Firm knowledge flow (but not knowledge stock) exhibited a significant positive main effect on firm innovation. Firm knowledge stock was not related significantly to firm innovation, but it became a significant predictor of firm innovation when existing along a high level of firm knowledge flow, as well as in firms adopting innovation strategies. The present study provides significant insights for researchers and practitioners by offering comprehensive understanding of the nomological network of firm‐level knowledge management enhanced by effective HRM practices.

PREDICTION MARKETS AS A DECISION SUPPORT TOOL IN DISASSEMBLING COMPANIES

Dp arts. However, due to the large number of dismantled parts and limited storage area, corresponding to the law requirements, it is necessary to anticipate the demand for the most sold parts. The high importance level of spare parts flow is a consequence of high economic potential as well as ecologic. Used spare parts are main source of revenues for disassembling companies, they are wanted by customers, and what is the most relevant – the utilization of used spare parts is the best scenario for products, which achieved end – of – life stage (vehicle). Disassembling companies mostly represents small and medium sized companies, what is related with low level of computerization, at each area of business activity, including recording parts selling and demand forecasting. In order to support decisions made at this area, it was prepared a concept of a tool based on the research method of predictive markets to anticipate the demand for used parts in dismantling facility. Predictive markets are based on the idea of crowdsourcing, using collective crowd intelligence to predict for example introduction of new medicines on the market, the directions of development of new technologies or competition activities. In the paper it was presented original approach to the demand forecasting in specific business which core flow is a reverse flow of waste.

Genetic monitoring of horses in the Czech Republic: A large-scale study with a focus on the Czech autochthonous breeds.

We propose the first comprehensive in-depth study monitoring horses in the Czech Republic. We scanned 9,289 animals from 44 populations for 17 equine STRs. Other equids analysed involved Equus przewalskii and Equus asinus. The total of 228 different alleles were detected, with the mean number of 13.4 per locus. The highest allelic richness (AR) was found in the Welsh Part Bred (6.01), followed by the Camargue (5.93) and Czech Sport Pony (5.91), whereas the Friesian exhibited the lowest AR (3.06). Interpopulation differences explained approximately nine per cent of the total genetic diversity. Reynold's genetic distance ranged from 0.003 between the Czech Warmblood and the Slovak Warmblood to 0.404 between the Friesian and donkeys. Close genetic proximity between the Silesian Noriker and Noriker was revealed. The Moravian Warmblood was better differentiated and more distant from the Czech Warmblood than the Kinsky Horse and retained the original genes of the old Austro-Hungarian tribes. A high gene flow level and a lack of genetic structure were found in the seven studied populations. Despite the historical bottlenecks and previous inbreeding, the Czech-Moravian Belgian Horse, Hucul, Old Kladruber Horse and Silesian Noriker did not suffer a serious loss of genetic diversity due to genetic drift/low effective population size. A NeighborNet dendrogram revealed breeds not classified in their groups according to the nomenclature (the Friesian, Hafling and Merens).

Dome-shaped transition between positive and negative interactions maintains higher persistence and biomass in more complex ecological networks

Positive relationship between diversity and biomass was often observed by empirical experiments at the community level, but the effects of species interactions on community total biomass have been rarely explored from a network perspective. Weak interaction and specific non-monotonic interactions have been proposed to be stabilizing mechanisms in maintaining persistence in more complex ecosystems, but it is unclear how they contribute to the high level of biomass or productivity of these systems. In this study, we examined the effects of various interactions, specifically dome-shaped (shifting from positive to negative effect with increase of density) and satiated interactions, on biomass and biomass flow with the increase of complexity in theoretical networks. Our results indicated that, as compared to linear or satiated interactions, dome-shaped interactions maintained both higher persistence and biomass or biomass flow in more complex networks, but resulted in larger variations of species biomass. However, variation of network biomass was much smaller than that of species biomass. Our results suggest that species interaction shifting between mutualism at low density and competition or predation at high density could be a driving force for maintaining high levels of persistence, diversity, biomass and biomass flow in natural ecosystems.

Ecological Operation Objectives for Four Major Chinese Carps Spawning in the Xijiang River

The river basin cascade development has prominent influence on water ecology for breeding of four major Chinese carps, and the determination of ecological operation objectives is an important basic work to carry out the ecological operation. This study determines the main control indexes of reservoir operation by analysing the relationships between larval population of Xijiang Dongta spawning ground and impact indexes like water temperature, flood process and flow velocity. Taking peak flow, initial discharge, flow rising range, daily increasing rate of flow and duration of water level rising of the spawning ground as the control indexes, the target flow process of reservoir ecological operation can be determined. Furthermore, the drifting velocity of fish eggs is used as the test index to control the section flow in the scheduling river reach. The proposed method is applied to the ecological operation of Dongta spawning ground, and the target flow processes of ecological operation under low, medium and high flow levels are obtained.

BV–VPIN: Measuring the impact of order flow toxicity and liquidity on international equity markets

Order flow is the measure of a trader's exposure to the risk that counterparties possess private information or other informational advantages. High levels of order flow can culminate in market makers providing liquidity at a loss or in the suboptimal execution of trades. From a regulatory perspective, high levels of can be harmful to overall market liquidity and precede precipitous drops in asset prices. The bulk volume-volume-synchronized probability of informed trading (BV-VPIN) model is one way of measuring the toxicity component of order flow, and it has been successfully applied in high-frequency trading environments. We apply the BV-VPIN to daily data from a range of international indexes in order to extend previous analyses of its properties. We find that a rise in BV-VPIN effectively foreshadows high levels of volatility in the equity indexes of several countries. If a BV-VPIN futures contract were to exist, we show that it would exhibit safe haven characteristics during market downturns. In particular, a simple active portfolio management strategy that times investments in equities (risk-free assets) when BV-VPIN levels are low (high) outperforms a buy-and-hold strategy. Thus, we find support for the application of BV-VPIN in international equity markets as a risk monitoring and management tool for portfolio managers and regulators.

BRAND RECALL WITHIN ADVERGAMES AND THE EFFECT OF THE HAND HELD CONTROLLER ON FLOW STATE IN INDIA

ABSTRACT This research examines consumer recall rates of advertising in video games and the effect the type of controller, hand held versus Natural User Interface (NUI) has on flow state. The natural user interface allows people to play video games where your body becomes the controller. The empirical data reported in this study indicated higher levels of flow and brand advertising recall when participants played a video game using a natural user interface without hand-held controller. These results held true for both aided and unaided advertising recall. Keywords Advergames, cognitive load, flow state, recall, natural user interface

Demographic and Well-Being Predictors of Regular and Long-term Practice of Argentine Tango in a Multicultural Sample of Practitioners

The practice of Argentine tango has experienced exponential growth all over the world, and several studies have revealed its positive outcomes on physical health. The present study aims to analyze demographic, well-being, and other psychological variables associated with the regular and long-term practice of Argentine tango. Participants included 524 men and women from 52 countries (Mean = 42.4; SD = 11.52; Range = 18–77). A multiple regression analysis was carried out designating the frequency of attendance at milongas as the dependent variable. Among women (n = 334), age, relationship situation, flourishing, and flow, emerged as significant predictors. Older and non-committed women, with a low level of flourishing, and a high level of flow were more likely to report a high frequency of tango practice. Among men (n = 190), relationship situation, flourishing, flow, and positive affects emerged as significant predictors. Non-committed men, with a low level of flourishing, a high level of flow, and a high level of positive affects were more likely to report a high frequency of tango practice. Another multiple regression analysis was conducted using the length of participants’ experience dancing tango as the dependent variable. Older and committed women with a high level of flow were more likely to report a pattern of long-term tango practice. Older men with a high level of flow were also more likely to be long-term practitioners of tango. These results raise questions about the potential effects of tango dancing on participants’ well-being.

Calling. Making the World a Better Place from Within Multinational Corporations

Nobody seems to doubt that working toward a calling is much more rewarding than just working for financial rewards or promotions. Nevertheless, although it is acknowledged that people can experience callings in any activity, up to now, there are few studies on this construct in the context of commercial companies. In this paper we focus on studying calling orientation in employees of a multinational company. We test three hypotheses: 1) the different ways of relating to work (as a job, a career or a calling) is also reported among corporate employees; 2) there are differences in the levels of flow at work in accordance with the different ways that employees relate to their work; and 3) there are differences in the levels of perception that employees have of the social relevance of their work in accordance with the way in which they relate to their work. In order to verify these hypotheses we applied three instruments to a sample of employees of the Latin America brand (279 Argentinean and 193 Ecuadorian employees) of a multinational corporation: The University of Pennsylvania Work Life Questionnaire, the Work Related Flow Inventory and a scale of Social Work Relevance Perception. The results suggest that callings are identifiable among corporate enterprise employees and that employees with a calling orientation have higher levels of flow at work and a greater perception of the social relevance of their work than those employees who just relate to their work as jobs or careers.

Дерматоліпектомія у пацієнтів із післяопераційною вентральною грижею за умов морбідного ожиріння

Мета роботи: розпрацювати тактичні передумови виконання реконструктивної абдомінопластики та герніопластики з імовірними варіантами корекції м’язово-апоневротичного шару передньої черевної стінки та адекватним вибором сітчастого імпланта та з урахуванням анатомічних і функціональних змін у ділянці операційного втручання.Матеріали і методи. Проаналізовано результати хірургічного лікування 46 пацієнтів із післяопераційною вентральною грижею (ПОВГ) із супутнім морбідним ожирінням за умов одночасного виконання алогерніопластики та дерматоліпектомії, з урахуванням результатів проведеного дослідження особливостей кровопостачання підшкірно жирового шару передньої черевної стінки у хворих із різним ІМТ. Вивчення гемодинаміки передньої черевної стінки у хворих із різним ІМТ дозволило нам визначити ділянки з інтенсивним та менш інтенсивним кровопостачанням, дослідити судини з різним діаметром та швидкістю кровотоку. Це стало доказовою базою вибору площі щадної мобілізації підшкірно-жирової клітковини під час виконання дерматоліпектомії.Результати досліджень та їх обговорення. В осіб з наявним III та IV ст. ожиріння з ІМТ=30–40 та >40 відмічено високий рівень кровотоку в мезо-гіпогастральній ділянці, особливо в ділянці грижових воріт, у надлобковій та пахових ділянках, із достовірно низьким рівнем кровопостачання та значним послабленням трофіки тканин на рівні вище пупка аж до реберних дуг. Водночас у хворих на ожиріння III ст. та морбідне ожиріння IV ст. найбільш активна візуалізація судин визначалась у нижніх відділах передньої черевної стінки, діаметр судин значно збільшувався, як і кількість судин із венозним типом кровотоку. Етап дерматоліпектомії виконували в основному за методиками Küster 10 (21,8 %) пацієнтам із вертикальним висіченням шкіри з підшкірно-жировою клітковиною, Jolly, Thorek – 32 (69,6 %) пацієнтам з видаленням тканин гіпогастральної ділянки горизонтальним доступом; у хворих із вираженим надлишком шкіри передньої черевної стінки виконували дерматоліпектомію комбінованим Т-подібним доступом за Castansres–Goethel – 4 (8,7 %). Вважаємо перспективним виконання симультанної дерматоліпектомії при алогерніопластиці з приводу ПОВГ при морбідному ожирінні з урахуванням особливостей кровопостачання підшкірно-жирової клітковини передньої черевної стінки та за умов зменшення площі скелетування підшкірно-жирового шару та виконання менш травматичної вертикальної, нижньої горизонтальної, в рідких випадках комбінованої дерматоліпектомії, що, в свою чергу, мінімізує ризики виникнення післяопераційних ускладнень.

Compartmentalized Regulation of Vascular Endothelial Cell Responses to Fluid Shear Stress by Phosphodiesterase 4D7 (PDE4D7)

While fast flowing blood in linear arterial segments exposes arterial vascular endothelial cells (VECs) to high levels of laminar fluid shear stress (FSS, 15–20 dyne/cm2), slow or oscillatory blood flow, such as is present at arterial bifurcations, exposes VECs to modest levels of non‐linear FSS (1–3 dyne/cm2). These hemodynamic features make arterial bifurcations, arches and branch points especially prone to atherosclerosis. Exposing VECs to high laminar FSS promotes establishment of an adaptive (anti‐thrombotic, anti‐atherogenic and barrier forming) phenotype, an effect that is reversed following exposure of these cells to low / non‐linear levels of FSS. Previously we reported that a cAMP‐signalosome, composed of exchange protein activated by cAMP1 (EPAC1), Rap1 and a phosphodiesterase 4D (PDE4D) allowed cAMP to promote barrier functions in static VEC cultures. This signalosome was shown to associate with components of VEC adherens junctions, including VE‐cadherin (VECAD) and β‐catenin. Recently, we reported that activation of this same AJ‐associated signalosome allowed cAMP, via EPAC1‐mediated activation of Rap1, to promote expression of an adaptive phenotype even in VECs exposed to low levels of FSS. Indeed, siRNA‐mediated knockdown of EPAC1, Rap1 or PDE4D reduced the adaptive responses of VECs exposed to FSS and increased their pro‐thrombotic and pro‐angiogenic potential. Interestingly, PDE4D knockdown reduced responses in these cells to levels equivalent to those detected in cells in which EPAC1 was knocked down. We reported that this effect was due to the fact that PDE4D acts as a tether to localize EPAC1 within this important cAMP‐signalosome. Recently we identified phosphodiesterase 4D7 (PDE4D7) as the PDE4D variant that populates this VEC cAMP‐signalosome. Notably, VEC alignment in the direction of flow was reduced by knockdown of either pan‐PDE4D, selective PDE4D7 or EPAC1 when subjected to low FSS. Both Pan‐PDE4D or selective PDE4D7 siRNA‐mediated knockdown markedly reduced the ability of VECs to respond adaptively to FSS, and promoted loss of EPAC1 from the cAMP‐signalosome. In contrast, PDE4 inhibitors only modestly altered these responses in VECs exposed to various levels of FSS. These findings, together with our earlier work, are consistent with the idea that the tethering actions of PDE4D7 are dominant in this complex in VECs. Using telomerase‐immortalized human aortic endothelial cells, we created a cell‐based system in which the separate catalytic and tethering actions of PDE4D7 in controlling VEC responses to FSS could be measured. Overall, our findings are consistent with the novel idea that the EPAC1 tethering function of PDE4D7 is dominant in regulating EPAC1/Rap1‐mediated effects in VECs and that the cAMP hydrolytic function of PDE4D7 has a hyperlocalized impact within the AJ‐delimited nanodomain. Our findings pave the way for the development of displacing peptide (DP)‐based tools through which to regulate cAMP‐mediated function in VECs exposed to mal‐adaptive levels of FSS.Support or Funding InformationFunding provided by the CIHR.

A mechanistic model of small intestinal starch digestion and glucose uptake in the cow

The high contribution of postruminal starch digestion (up to 50%) to total-tract starch digestion on energy-dense, starch-rich diets demands that limitations to small intestinal starch digestion be identified. A mechanistic model of the small intestine was described and evaluated with regard to its ability to simulate observations from abomasal carbohydrate infusions in the dairy cow. The 7 state variables represent starch, oligosaccharide, glucose, and pancreatic amylase in the intestinal lumen, oligosaccharide and glucose in the unstirred water layer at the intestinal wall, and intracellular glucose of the enterocyte. Enzymatic hydrolysis of starch was modeled as a 2-stage process involving the activity of pancreatic amylase in the lumen and of oligosaccharidase at the brush border of the enterocyte confined within the unstirred water layer. The Na+-dependent glucose transport into the enterocyte was represented along with a facilitative glucose transporter 2 transport system on the basolateral membrane. The small intestine is subdivided into 3 main sections, representing the duodenum, jejunum, and ileum for parameterization. Further subsections are defined between which continual digesta flow is represented. The model predicted nonstructural carbohydrate disappearance in the small intestine for cattle unadapted to duodenal infusion with a coefficient of determination of 0.92 and a root mean square prediction error of 25.4%. Simulation of glucose disappearance for mature Holstein heifers adapted to various levels of duodenal glucose infusion yielded a coefficient of determination of 0.81 and a root mean square prediction error of 38.6%. Analysis of model behavior identified limitations to the efficiency of small intestinal starch digestion with high levels of duodenal starch flow. Limitations to individual processes, particularly starch digestion in the proximal section of the intestine, can create asynchrony between starch hydrolysis and glucose uptake capacity.

Muscle Tissue Saturation Compared With Muscle Tissue Perfusion During Low Blood Flows: An Experimental Study

To investigate whether changes in muscle tissue perfusion measured with positron emission tomography would be reflected by parallel changes in muscle tissue oxygen saturation (StO2) measured using near-infrared spectroscopy during high and low blood flow levels achieved using cardiopulmonary bypass (CPB) in an animal model. A prospective, randomized study. Research laboratory, single institution. Eight pigs (69-71 kg). In anesthetized pigs, normothermic CPB was established with a blood flow of 60 mL/kg/min for 1 hour. Thereafter, a low blood flow of either 47.5 or 35 mL/kg/min was applied for 1 hour followed by a blood flow of 60 mL/kg/min for an additional hour. Regional StO2 was measured continuously by placing a near-infrared spectroscopy electrode on the skin above the gracilis muscle of the noncannulated back leg. Muscle tissue perfusion was measured using positron emission tomography with 15O-labeled water during spontaneous circulation and the different CPB blood flows. Systemic oxygen consumption was estimated by measurement of venous saturation and lactate levels. The results showed profound systemic ischemia during low CPB blood flow. StO2 remained high until muscle tissue perfusion decreased to about 50%, after which StO2 paralleled the linear decrease in muscle tissue perfusion. In an experimental CPB animal model, StO2 was stable until muscle tissue perfusion was reduced by about 50%, and at lower blood flow levels, there was almost a linear relationship between StO2 and muscle tissue perfusion.

Self-determination theory applied to flow in conservatoire music practice: The roles of perceived autonomy and competence, and autonomous and controlled motivation

Self-determination theory (SDT) postulates that environments providing psychological needs satisfaction (PNS) promote quality motivation, thus enhancing engagement and performance in diverse performance domains. SDT and PNS were used to investigate student experience of conservatoire instrument practice. Participants ( N = 162) completed standardized self-report questionnaires. Associations between study variables were described and hierarchical multiple regression analysis was conducted to assess the predictive effects of autonomy and competence needs satisfaction and autonomous and controlled motivation on inter-subject flow variations. A considerable part of flow variations was accounted for by study variables. Results showed that conservatoire students, especially those studying instrument performance ( n = 109), reported high levels of flow, perceived competence and autonomy, and intrinsic motivation. Autonomous motivation had a direct effect on flow variations, whereas controlled motivation had an inverse effect. Perceived competence was the strongest predictor of flow variations and it was also associated with external regulation (especially among students studying instrument performance), thus indicating that intrinsic and extrinsic motives both play important roles in conservatoire instrument practice. Conservatoire instrument teachers need to acknowledge that perceived competence is critical to flow in instrument practice, in order to provide their students with optimal challenges that avoid frustration and amotivation.

Abstract A49: Tumor-associated interstitial flow promotes macrophage migration and pro-metastatic M2 phenotype in 3D ECM

Abstract The growth of solid tumor is often accompanied by an increase in the flow of interstitial fluid (interstitial flow) from the center of the tumor to the surrounding stroma. Recent studies have shown that elevated interstitial flow can influence the migration of cancer cells and fibroblasts. Despite these findings, the effects of interstitial flow on macrophages, one of the key metastasis-promoting tumor-associated stromal cell types, have not been explored. We used microfluidic and transwell flow assays to investigate how high level of interstitial flow (~3 μm/s) often observed in tumor affect macrophage migration and protein expression. We found that interstitial flow not only enhanced macrophage migration speed, but also directed macrophages to migrate against the flow in 3D extracellular matrix. Moreover, we discovered that interstitial flow activated Akt and FAK, two kinases that are crucial for cell migration. Interestingly, interstitial flow also up-regulated macrophage expression of M2 markers Arg I and TGFβ through the activation of JAK1-STAT3/6 pathway. Finally, macrophages treated with interstitial flow were shown to have enhanced abilities to promote cancer cell migration and protrusion formation. Taken together, these results suggest that interstitial flow can promote metastasis through its effects on macrophages. Specifically, since macrophages migrate against the flow, interstitial flow, which emanates from the tumor, can act as a mechanical stimulus to recruit macrophages into tumor tissues. Moreover, interstitial flow can activate macrophages and polarize them toward pro-metastatic M2 phenotype to further promote tumor metastasis and immunosuppression. Citation Format: Ran Li, Hao Xing, Tara A. Lee, Hesham Azizgolshani, Roger D. Kamm. Tumor-associated interstitial flow promotes macrophage migration and pro-metastatic M2 phenotype in 3D ECM. [abstract]. In: Proceedings of the AACR Special Conference on Engineering and Physical Sciences in Oncology; 2016 Jun 25-28; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2017;77(2 Suppl):Abstract nr A49.

Population structuring of selected mungbean landraces of the Odisha State of India via DNA marker-based genetic diversity analysis

Ever-increasing demands of mungbean consumption, wide eco-geographical variations and inadequate achievements through conventional breeding necessitate comprehensive assessment of genetic variability coupled with population patterning. In the present work 30 mungbean landraces of the Odisha State of India representing four different geographical regions (populations) along with some Indian genotypes were used for elucidation of genetic diversity and population structure analysis using 52 SCoT (gene-targeted) and 45 RAPD (arbitrary) markers. SCoT markers proved to be more effective than RAPD in ascertaining genetic diversity at genotype level (% polymorphism, Rp, PIC, EMR, MI, GI and I) and population level (Na, Ne, H, I, Ht and Hs). Unique bands (23 RAPD and 47 SCoT) were generated which enabled identification of 16 and 25 genotypes respectively. Genetic diversity parameters of East Odisha revealed high genetic variability compared to other populations. AMOVA revealed >95% variation within the populations which is further supported by high gene flow and low level of genetic differentiation. UPGMA dendrogram and population structure grouped genotypes into 8 major clusters irrespective of their geographical affiliations. However, genotypes belonging to certain clusters exhibited significant geographical and morphological preferences using the cumulative strategy. The study illustrated the importance of combined marker analysis, which uses complementary information from two distinct and analogous markers and in the process, offers accurate and reliable results. Further, the applicability of in silico analysis in performing a high resolution patterning of genetic divergence and population structure was demonstrated.

People, processes, and systems: An observational study of the role of technology in rural youth mental health services

The merits of technology-based mental health service reform have been widely debated among academics, practitioners, and policy makers. The design of new technologies must first be predicated on a detailed appreciation of how the mental health system works before it can be improved or changed through the introduction of new products and services. Further work is required to better understand the nature of face-to-face mental health work and to translate this knowledge to computer scientists and system designers responsible for creating technology-based solutions. Intensive observation of day-to-day work within two rural youth mental health services in South Australia, Australia, was undertaken to understand how technology could be designed and implemented to enhance young people's engagement with services and improve their experience of help seeking. Data were analysed through a lens of complexity theory. Results highlight the variety of professional roles and services that can comprise the mental health system. The level of interconnectedness evident in the system contrasted with high levels of service self-organization and disjointed information flow. A mental health professional's work was guided by two main constructs: risk and engagement. Most clients presented with a profile of disability, disadvantage, and isolation, so complex client presentations and decision-making were core practices. Clients (and frequently, their families) engaged with services in a crisis-dependent manner, characterized by multiple disengagements and re-engagements over time. While significant opportunities exist to integrate technology into existing youth mental health services, technologies for this space must be usable for a broad range of medical, psychological and cognitive disability, social disadvantage, and accommodate repeat cycles of engagement/disengagement over time.

The impact of uncertainty on payout policy

Purpose The purpose of this paper is to investigate the impact of market-level uncertainty on dividend and repurchase decisions. Design/methodology/approach Using a large data set over a nearly 50-year period, the author examines the choice to pay dividends and repurchase shares using logit and multinomial logit regressions. Findings Market-level uncertainty (measured by a GARCH estimate of volatility, as well as the Chicago Board Options Exchange Volatility Index) is shown to have a statistically significant impact on firms’ payout policy decisions. This impact is different for dividends and repurchases as well as for firms with differing levels of cash flows. As market uncertainty increases, firms with low cash flow levels tighten dividend policy to conserve cash while firms with high cash flow levels become opportunistic through the use of share repurchases. Practical implications The findings allow investors to better understand the connection between shifts in market-level uncertainty and corporate payout policy, specifically through the differing use of dividends and repurchases. Originality/value While prior literature on payout policy has focused on firm-level determinants, this study demonstrates that market-level uncertainty impacts firms’ payout policy decisions uniquely. Furthermore, this is, to the author’s knowledge, the first study to differentiate by relative cash flow level, demonstrating that not all cash flow levels react in the same manner.

Photosynthesis and Photosynthetic Electron Flow in the Alpine Evergreen Species Quercus guyavifolia in Winter.

Alpine evergreen broadleaf tree species must regularly cope with low night temperatures in winter. However, the effects of low night temperatures on photosynthesis in alpine evergreen broadleaf tree species are unclear. We measured the diurnal photosynthetic parameters before and after cold snap for leaves of Quercus guyavifolia growing in its native habitat at 3290 m. On 11 and 12 December 2013 (before cold snap), stomatal and mesophyll conductances (gs and gm), CO2 assimilation rate (An), and total electron flow through PSII (JPSII) at daytime were maintained at high levels. The major action of alternative electron flow was to provide extra ATP for primary metabolisms. On 20 December 2013 (after cold snap), the diurnal values of gs, gm, An, and JPSII at daytime largely decreased, mainly due to the large decrease in night air temperature. Meanwhile, the ratio of photorespiration and alternative electron flow to JPSII largely increased on 20 December. Furthermore, the high levels of alternative electron flow were accompanied with low rates of extra ATP production. A quantitative limitation analysis reveals that the gm limitation increased on 20 December with decreased night air temperature. Therefore, the night air temperature was an important determinant of stomatal/mesophyll conductance and photosynthesis. When photosynthesis is inhibited following freezing night temperatures, photorespiration and alternative electron flow are important electron sinks, which support the role of photorespiration and alternative electron flow in photoportection for alpine plants under low temperatures.