Vertical Leader Research Articles

Does Shared Leadership Always Have Positive Effects on Employee Creativity? A Role Conflict Perspective

Drawing on role theory, this study investigates the cross-level impact of shared leadership on employee creativity via role conflict, and further explores the boundary condition of task-oriented vertical leader behavior. Data were collected from 691 employees and their direct leaders from 93 teams in China. The results reveal that (a) shared leadership increases role conflict, (b) shared leadership negatively affects employee creativity through role conflict, and (c) task-oriented vertical leader behavior weakens the impact of shared leadership on role conflict and the negative indirect impact of shared leadership on employee creativity. This study enriches the literature on leadership and creativity by revealing the potential inhibiting effect of shared leadership on creativity and the mitigating effect of vertical leadership behavior.

Shared leadership in MNC agile software teams: The role of team leadership style and attitude to sport

This study investigates whether and how vertical leader transformational and transactional styles impact team members' perceptions of shared leadership. It also investigates the mediating role of a leader's attitude to sport on these relationships. Using a matched sample of 154 team leaders and 354 team members from agile teams in two MNCs located in Ireland and China, we found that both vertical transformational and transactional leadership were linked to team members' shared leadership behavior; however, the impact of transformational leadership was significantly greater. We also found that a vertical team leader's attitude to sports, and specifically the pleasure and participation attitude, positively mediated the relationship between transformational and transactional leadership and shared leadership behavior. This contrasted with the power and performance sports attitude, which mediated both transformational and transactional leadership styles, but for which the impact of transactional leadership on shared leadership became negative. We extend research on the antecedents of shared leadership and the important role that both a vertical leader's style and attitudes play within an agile software team. We discuss implications for theory and practice.

An approach-inhibition model of shared leadership: the effect of vertical leader’s multi-source power

PurposeDrawing on power approach-inhibition theory, this study develops a conditional indirect effect model to explore how team vertical leader position and expert power indirectly impact members’ shared leadership through vertical leader’s empowering behaviors.Design/methodology/approachMulti-source data was collected using a field survey research design. The final sample includes 944 employees in 164 teams from 14 companies in China.FindingsThis study found that the interaction of team vertical leader position power and expert power was positively related to their empowering behaviors, which in turn were positively associated with shared leadership. Moreover, our post hoc-analysis revealed the moderating effect of team power distance orientation on the relationship between vertical leader empowering behaviors and shared leadership.Originality/valueThis study sheds light on shared leadership literature by examining vertical leader position and expert power as antecedents. We also offer new directions for exploring how power functions by discussing leadership through the lens of power approach-inhibition theory.

Comparison of the yielding of plum, sour cherry, and sweet cherry trees trained to a trellis for mechanical harvesting of fruit with those trained to a leader

In 2014, plum, sour cherry and sweet cherry trees were planted in an experimental plot of the Institute of Horticulture – National Research Institute at a distance of 4.5 m between rows and, depending on the cultivar, every 1.5, 2.0 and 2.5 m in a row. The trees were trained in the shape of the letter ‘Y’, with the shoots raised at an angle of 20° or 30° to the horizontal, intended for mechanical harvesting of dessert fruit with a harvester attached to a tractor. The two tree canopy formation systems at both shoot inclination angles were compared with the standard spindle crown with a vertical leader, from which the fruit was picked by hand. After 3 years of training the trees, mechanical harvesting of dessert fruit began with a harvester designed at the Institute of Horticulture in Skierniewice. The trees formed in the shape of the letter ‘Y’ produced comparable yields, and also higher and lower yields, depending on the cultivar, in comparison with the trees trained to a spindle crown.

The Effect of Vertical Leader’s Multi-Source Power on Shared Leadership

The Effect of Vertical Leader’s Multi-Source Power on Shared Leadership

Analysis of Metal Oxide Varistor Arresters for Protection of Multiconductor Transmission Lines Using Unconditionally-Stable Crank–Nicolson FDTD

Surge arresters may represent an efficient choice for limiting lightning surge effects, significantly reducing the outage rate of power lines. The present work firstly presents an efficient numerical approach suitable for insulation coordination studies based on an implicit Crank–Nicolson finite difference time domain method; then, the IEEE recommended surge arrester model is reviewed and implemented by means of a local implicit scheme, based on a set of non-linear equations, that are recast in a suitable form for efficient solution. The model is proven to ensure robustness and second-order accuracy. The implementation of the arrester model in the implicit Crank–Nicolson scheme represents the added value brought by the present study. Indeed, its preserved stability for larger time steps allows reducing running time by more than 60 % compared to the well-known finite difference time domain method based on the explicit leap-frog scheme. The reduced computation time allows faster repeated solutions, which need to be looked for on assessing the lightning performance (randomly changing, parameters such as peak current, rise time, tail time, location of the vertical leader channel, phase conductor voltages, footing resistance, insulator strength, etc. would need to be changed thousands of times).

Gibberellic Acid<sub>4+7</sub> and Benzyladenine, Cambium Disconnection, Nitrogen, and Tip Removal Influence on Branch Induction in Newly Planted Poorly Feathered “Fuji” Apple Trees

The use of well-feathered nursery trees on dwarfing rootstocks is crucial for establishing high-density apple orchards to ensure early production. Training trees to develop a tall spindle canopy architecture has gained popularity in high-density orchards during the past decade. However, commercially produced nursery trees often lack feathers or are unevenly branched, making initial training decisions difficult and delaying precocious fruiting. In this project, we studied the vegetative meristem activation response to partial scoring or partial girdling of the bark cambium above the bud, with and without application of 500 ppm Promalin (gibberellin4+7 + benzyladenine), tip removal of the tree leader at the silver tip stage on April 23, 2019, Promalin spray at 500 ppm at post-bloom stage on May 7, 2019, and nitrogen (N) as UAN-32 (32% N) application at five levels (60, 80, 100, 120, or 140 g actual N/tree) on June 20, 2019, in newly planted un-feathered or unevenly branched “Aztec Fuji” trees on Budagovsky 9 (Bud 9) in southwest Idaho, USA. Grower’s Short Cut trees received a heading cut to the leader at 60 cm above the ground and resulted in the emergence of 5 - 6 strong branches near the heading cut. These trees had larger trunk cross-sectional areas than scored or girdled trees. Scoring or girdling, with or without Promalin, significantly improved branching by increasing the number of branches and bourse shoots. In many cases, the effects of partial scoring, with or without Promalin, were similar to those of bark girdling which is a more risky and time-consuming process. Branches induced by scoring and girdling had sharper crotch angles relative to the vertical leader. Spraying Promalin during the post-bloom stage at 500 ppm was not as effective as scoring or girdling to initiate branches. Additional N rates or removal of the leader tip did not significantly impact branch induction.

Proactive Leadership in the Supply Chain of a Multinational Enterprise

Leadership factors influence change effort needed to achieve desired outcomes. Effort is significantly increased when agendas are multiple and conflicting. Proactive leaders need to be able to lead and make leaders. While standing on a platform of suitable norms and excellent performance, a vertical leader can set strategic growth plans proactively. Typically these plans are reactively conjured up and they are less effective. This study shows that the proactive leader needs to be a steward of the capacity given while continuously improving its effectiveness. The evidence from this study suggests that proactive leaders that effectively influence in an MNE are critical to growth synergies in a multi-unit global enterprise in a moderately dynamic market. Furthermore, effective focused strategy applied proactively leads to improved profitability.

Multirow Boundary-Labeling Algorithms for Panorama Images

Boundary labeling deals with placing annotations for objects in an image on the boundary of that image. This problem occurs frequently in situations in which placing labels directly in the image is impossible or produces too much visual clutter. Examples are annotating maps, photos, or technical/medical illustrations. Previous algorithmic results for boundary labeling consider a single layer of labels along some or all sides of a rectangular image. If, however, the number of labels is large or the labels are too long, multiple layers of labels are needed. In this article, we study boundary labeling for panorama images, where n points in a rectangle R are to be annotated by disjoint unit-height rectangular labels placed above R in K different rows (or layers). Each point is connected to its label by a vertical leader that does not intersect any other label. We present polynomial time algorithms based on dynamic programming that either minimize the number of rows to place all n labels or maximize the number (or total weight) of labels that can be placed in K rows for a given integer K . For weighted labels, the problem is shown to be (weakly) NP-hard; in this case, we give a pseudo-polynomial algorithm to maximize the weight of the selected labels. We have implemented our algorithms; the experimental results show that solutions for realistically sized instances are computed instantaneously. We have also investigated two-sided panorama labeling, for which the labels may be placed above or below the panorama image. In this model, all of the aforementioned problems are NP-hard. For solving them, we propose mixed-integer linear program formulations.

Humility in Teams: Collective Humility and Its Impact on Team Growth Climate and Performance

To further understand the relevance and benefits of humility in organizations, in this study we introduce and explore the concept of collective humility, a team-level interpersonal process that we propose leads to a collective focus on team growth (or team growth climate). To establish construct validity, we conceptually and empirically differentiate collective humility from other team-level constructs. Using a simulation study from the lab (192 participants in 53 teams), we establish the predictive validity of collective humility, showing it leads to a team growth climate and higher team performance. Using a field sample from a healthcare context (326 participants in 75 teams), we test and find support for a theoretical model wherein vertical leader humility fosters collective humility, which in turn fosters a team climate of growth, leading to higher team performance. We conclude with discussion of theoretical implications, limitations, and potential areas for future research.

“Chaotic” dart leaders in triggered lightning: Electric fields, X‐rays, and source locations

We present the first published observations of “chaotic” dart leaders in triggered‐lightning discharges. We examine four leaders that exhibited “chaotic” electric field derivative (dE/dt) signatures in their final 10 to 12 μs. The dE/dt signatures were characterized by bursts exhibiting widths of the order of hundreds of nanoseconds on which were superimposed irregular pulses with widths of the order of tens of nanoseconds. These unique signatures were dissimilar from the dE/dt waveforms observed from dart or dart‐stepped leaders in triggered lightning. Three‐dimensional locations for dE/dt pulses that radiated from the bottom 200 m of the leader channels were determined, as were emission times. Vertical leader speeds for the four “chaotic” dart leaders were estimated to range from 2.0 to 4.3 × 107 m/s. A relatively continuous flux of energetic radiation (X‐rays and gamma rays) was observed during the final 10–13 μs of each “chaotic” dart leader. Some individual photons had energies more than 1 MeV. High‐speed video images of three “chaotic” dart leaders were obtained at a frame rate of 300 kilo‐frames per second (exposure time of 3.33 μs). One image, in the frame immediately prior to the return stroke, shows an upward positive leader 11.5 m in length propagating from the launch facility and a downward negative leader above with a streamer zone length of about 25 m. Channel base currents preceding the four “chaotic” dart leaders were of unusually long duration and large charge transfer, and return strokes following them had larger than usual peak currents.

Apparent Increase in Biomass and Seed Productivity in Hemp(Cannabis sativa)Resulting from Branch Proliferation Caused by the European Corn Borer(Ostrinia nubilalis)

Abstract The European corn borer (Ostrinia nubilalis Hubner), or ECB, is a major pest of hemp (Cannabis sativa L.). During the course of a study of hemp germplasm and cultivar accessions, the ECB attacked the vertical stem leader of hundreds of plants. At the site of invasion the main stem was typically destroyed, and the plant became strongly branched. Although the damaged plants were an average 9% shorter, mean shoot weight was 20% heavier. Seed productivity was also greater, based on a visual scale. The practical significance of such an “overcompensation” response to insect damage, with damaged plants growing more robustly and productively than their undamaged counterparts, is controversial. Certainly, some aspects of productivity, such as fibre quality, are detrimentally affected by the ECB. The insect showed a preference for larger plants, but was indifferent to the level of tetrahydrocannabinol, the chief intoxicant of C. sativa.

Response of Subalpine Conifers in the Sierra Nevada, California, U.S.A., to 20th-Century Warming and Decadal Climate Variability

Four independent studies of conifer growth between 1880 and 2002 in upper elevation forests of the central Sierra Nevada, California, U.S.A., showed correlated multidecadal and century-long responses associated with climate. Using tree-ring and ecological plot analysis, we studied annual branch growth of krummholz Pinus albicaulis; invasion by P. albicaulis and Pinus monticola into formerly persistent snowfields; dates of vertical branch emergence in krummholz P. albicaulis; and invasion by Pinus contorta into subalpine meadows. Mean annual branch growth at six treeline sites increased significantly over the 20th century (range 130–400%), with significant accelerations in rate from 1920 to 1945 and after 1980. Growth stabilized from 1945 to 1980. Similarly, invasion of six snowfield slopes began in the early 1900s and continued into snowfield centers throughout the 20th century, with significantly accelerated mean invasion from 1925 to 1940 and after 1980. Rate of snowfield invasion decreased between 1950 and 1975. Meadow invasion and vertical leader emergence showed synchronous, episodic responses. Pinus contorta invaded each of ten subalpine meadows in a distinct multidecadal pulse between 1945 and 1976 (87% of all trees) and vertical release in five krummholz P. albicaulis sites also occurred in one pulse between 1945 and 1976 (86% of all branches). These synchronies and lack of effect of local environments implicate regional climate control. Composite weather records indicated significant century-long increases in minimum monthly temperature and multidecadal variability in minimum temperature and precipitation. All ecological responses were significantly correlated with minimum temperature. Significant interactions among temperature, precipitation, Pacific Decadal Oscillation (PDO) indices, and multiyear variability in moisture availability further explained episodic ecological responses. Four multidecadal periods of the 20th century that are defined by ecological response (<1925; 1925–1944; 1945–1976; >1976) correlate with positive and negative PDO phases, as well as with steps in the rate of temperature increase. These diverse factors in spatially distributed upper-montane and treeline ecosystems respond directionally to century-long climate trends, and also exhibit abrupt and reversible effects as a consequence of interdecadal climate variability and complex interactions of temperature and moisture.

The future of leadership: Combining vertical and shared leadership to transform knowledge work

Executive Overview Knowledge work is becoming increasingly team-based. The reason is clear. It is becoming ever more difficult for any one person to be an expert on all aspects of the work that needs to be done, and this is true in a wide variety of contexts ranging from the R&D lab to the executive suite. With the shift to team-based knowledge work comes the need to question more traditional models of leadership. Traditionally, leadership has been conceived around the idea that one person is firmly “in charge” while the rest are simply followers—what is termed vertical leadership. However, recent research indicates that leadership can be shared by team leaders and team members—rotating to the person with the key knowledge, skills, and abilities for the particular issues facing the team at any given moment. In fact, research indicates that poor-performing teams tend to be dominated by the team leader, while high-performing teams display more dispersed leadership patterns, i.e., shared leadership.1 This is not to suggest that leadership from above is unnecessary. On the contrary, the role of the vertical leader is critical to the ongoing success of the shared-leadership approach to knowledge work. Thus, this article addresses the following questions: (1) when is leadership most appropriately shared? (2) how is shared leadership best developed? and (3) how does one effectively utilize both vertical and shared leadership to leverage the capabilities of knowledge workers?

Analysis of air termination system of the lightning protection scheme for the Indian satellite launch pad

Any satellite launch mission is a complex and expensive process and great care and precautions need to be taken for a safe and successful launch. A lightning stroke can be hazardous to the satellite launch system. Therefore extensive care has to be taken to protect the satellite launch pad against lightning. The paper aims at evaluating the efficacy of the aerial receptor system of the lightning protection scheme employed for protecting the Indian satellite launch pad. Significant upward leader activities are expected from tall objects during the approach of the descending leader and therefore any method that is employed for evaluating their attractive radii must take into account the different process involving and connected with the breakdown of air. Among such models the Rizk model, originally developed for isolated towers and conductors, was found to be very appropriate for the present work. To apply it to the present problem many modifications were necessary; all the simulations were carried out using this modified model. The charge simulation method has been used for the computation of the electric field. Simulations with inclined downward leaders indicated that the vertical leader descent represents the worst case scenario, and hence all the calculations were carried out with a vertical leader descent only. The maximum current in a bypass stroke was found to be 14 kA and this occurs for a stroke descending vertically along a straight line directly above the launch vehicle. The total probability of bypass strokes was found to be in the range of one flash per 1095-510 years (for the value of Td which is reported to be between 50-90 thunderstorm-days per year). Similarly, the total number strokes to the protection system in an year was estimated to be less than two flashes per year. Further, some sensitivity analysis was also carried out to determine the dependency of bypass stroke on height of the protection system and total length of the descending leader. An attempt was also made to arrive at a rough estimate of maximum bypass current under positive lightning.

LF/VLF and VHF lightning fast‐stepped leader observations

This paper reports multiplatform observations of leader radiation preceding initial cloud‐to‐ground lightning return strokes by &lt;6 ms. Specifically, we present multistation ground‐based LF/VLF recordings of events with large‐amplitude leader activity (comparable in amplitude to the return stroke amplitude). The events were selected for their coincidence with VHF observations by the FORTE satellite. Some FORTE VHF leader step observations have obvious direct and ground reflection components. For these steps, which temporally correspond to specific features in the ground LF/VLF field change records, we calculate a source height based on event satellite geometry. We determine source heights between 4.0 and 5.5 km. For FORTE records with multiple reflected events we calculate vertical leader propagation velocities on the order of 106 m/s. The determined vertical leader propagation speeds are an order of magnitude greater than those reported as typical values for stepped leader velocities associated with initial return strokes.

Model of electric charges in thunderstorms and associated lightning

An axisymmetrical electrostatic model of charges in a thunderstorm cloud at the mature stage is used to initiate a bidirectional vertical leader that develops into either a cloud‐to‐ground or an intracloud flash from the regions of maximum electric field. The principal result of this study is the determination of the physical and quantitative relationships among cloud charges, potentials, and electric fields, and the induced charges, currents, and electric field changes of the lightning channel from the numerical solution of the Poisson equation for a cloud charge model with lightning. An important consequence of the model is that the upper part of the cloud‐to‐ground leader and the lower part of the intracloud leader terminate inside the cloud.