2,846 research outputs found
Women in Business Leadership
Abstract
Female participation in business leadership, throughout the world, has traditionally been significantly less than their male counterparts. Various factors have been mentioned to be the cause of this issue. These include gender biases in the workplace and in cultural obligations, familial responsibilities, access to education, lack of female mentors and role models in leadership roles, as well as obstacles in advancement and gaps in compensation. It has been shown that gender bias is a strong motivator for the lack of female presence in business overall, but significantly so for leadership roles. Based on the expectations in our culture as well as many others, women have traditionally been regarded as caretakers of the home environment primarily and as less adept in âmale-dominatedâ fields and roles.
This paper seeks to define and discuss the current status for women in business leadership. This information will include the statistics for female representation in business leadership roles and board membership on a global scale and will include contrasting data for both male representation and for different countries. Additionally, gender biases and cultural differences and their effect on these statistics will be included, as well as other external and internal obstacles presented by both male and female alike. By examining the phenomenon of exclusion in this particular case, this paper will seek to find possible solutions to assist womenâs participation in boards and as executives in the business world
Alternatives to distillation: multi-membrane permeation and petrol pre-blending for bio-ethanol recovery
A thesis submitted for the degree of Doctor of Philosophy to The Department of Chemical and Metallurgical Engineering, Faculty of Engineering, University of the Witwatersrand, Johannesburg, 2016Separation of materials is crucial to the operation of the majority of chemical processes, not only for the purification of final products but also for the processing of feed-stocks prior to chemical reaction. The most commonplace method of materials separation is distillation which, unfortunately, is often an energy-intensive process and contributes significantly to mankindâs energy consumption and carbon dioxide emissions.
Alternative approaches to separation are therefore a crucial element of the ongoing pursuit for sustainability in chemical industries. There are two principal ways of going about this. The first is to replace distillation units with alternative unit operations that can achieve the same separation with less energy expenditure. The second approach is overall flowsheet revision, fundamentally changing a separation cycle to minimize its energy requirements.
The greatest improvements to energy efficiency will be achieved by applying both approaches in tandem. However, each must be developed separately to make that possible.
This thesis lays the groundwork for radical revision of major separation operations by showcasing a new overall flowsheet for bioethanol separation that promises tremendous improvements in separation efficiency, reducing the energy usage involved in ethanol purification by as much as 40% in some scenarios.
It also develops a novel method for the design of multi-membrane permeation units, showing how area ratio can be manipulated to fundamentally alter separation performance from such units, resulting in superior separation performance to conventional units, achieving higher recoveries than conventional setups.
With membranes being an increasingly popular separation method, the potential for superior performance from multi-membrane units promises improvements in separation efficiency
A Biomimetically Derived Method for Control of Span-Wise Morphing Wings
© 2022 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved. This is the accepted manuscript version of a conference paper which has been published in final form at https://doi.org/10.2514/6.2022-1986The development of novel morphing wings follows common milestones. This work presents the modelling and control of the recently proposed avian wing span-wise morphing concept. The concept primarily consists of three structural members heavily mimicking the skeletal structure birds employ for flight. This structure is actuated, through the range of motion achievable by avian, with the integration of pneumatic artificial muscles (PAMs). Arranged in antagonistic pairs, the PAMs actuate an effective shoulder joint between the aircraft and wing through 90â°. As well as two joints along the wing through 110â°, allowing a span-wise reduction of 75% the fully extended span. This adaptive structure is capable of supporting several different aerofoil geometries for application specific aircraft. Initially proposed with a biomimetic derived wing profile more traditional and predictable NACA aerofoils have been applied. In this paper the avian wing span-wise morphing concept is modelled and with the application of inverse kinematics a control system is derived to allow simplified span-length positioning. Similarly, desired wing area is also presented as an input for the system. The model is based on PAM force models to individually model the pneumatic system driving each joint. The mechanical system of each joint is subsequently used to produce a direct kinematic model for wing tip position, and the inverse determined for control. The validity of both the model and system are experimentally tested on a fixed semi-span prototype rig of the morphing concept. Feedback is then introduced. Potentiometers are embedded into each joint to provide joint angle feedback. The tuning of the system is then presented for different dynamic responses. Alongside this development experiments have been conducted into the kinematics avian employ in flight and the flight dynamics they enable. These results are presented and directly applied as parameters for the proposed system. Span morphing retraction and extension rates determined from in vivo flight data of avian, including the Common buzzard (Buteo buteo) and Harris Hawk (Parabuteo unicinctus), are achieved using the avian wing span-wise morphing concept and the proposed control system. These dynamics are used to infer the parameters of an aircraft with the concept wing used as control surfaces
A Hybrid Approach to Privacy-Preserving Federated Learning
Federated learning facilitates the collaborative training of models without
the sharing of raw data. However, recent attacks demonstrate that simply
maintaining data locality during training processes does not provide sufficient
privacy guarantees. Rather, we need a federated learning system capable of
preventing inference over both the messages exchanged during training and the
final trained model while ensuring the resulting model also has acceptable
predictive accuracy. Existing federated learning approaches either use secure
multiparty computation (SMC) which is vulnerable to inference or differential
privacy which can lead to low accuracy given a large number of parties with
relatively small amounts of data each. In this paper, we present an alternative
approach that utilizes both differential privacy and SMC to balance these
trade-offs. Combining differential privacy with secure multiparty computation
enables us to reduce the growth of noise injection as the number of parties
increases without sacrificing privacy while maintaining a pre-defined rate of
trust. Our system is therefore a scalable approach that protects against
inference threats and produces models with high accuracy. Additionally, our
system can be used to train a variety of machine learning models, which we
validate with experimental results on 3 different machine learning algorithms.
Our experiments demonstrate that our approach out-performs state of the art
solutions
Facing the Medusa: Confronting the Ongoing Impossibility of Womenâs Studies
From the Introduction:
When feminism is defined in such a way that it calls attention to the diversity of womenâs social and political reality, it centralizes the experiences of all women, especially the women whose social conditions have been least written about, studied, or changed by political movements. When we cease to focus on this simplistic stance âmen are the enemy,â we are compelled to examine systems of domination and our role in their maintenance and perpetuation. Lack of adequate definition made it easy for bourgeois women, whether liberal or radical in perspective, to maintain their dominance over the leadership of the movement and its direction. This hegemony continues to exist in most feminist organizations. Exploited and oppressed groups of women are usually encouraged by those in power to feel that their situation is hopeless, that they can do nothing to break the pattern of domination. Given such socialization, these women have often felt that our only response to white, bourgeois, hegemonic dominance of feminist movement is to trash, reject, or dismiss feminism. This reaction is in no way threatening to those women who wish to maintain control over the direction of feminist theory and praxis. They prefer us to be silent, passively accepting their ideasâŠ(T)here has been a shift within the womenâs movement whereby critique no longer focuses merely on patriarchal social structures but also on white middle- class womenâs perpetuation of them to the detriment of other women and possibly to the demise of the womenâs studies movement in its entirety. Such a juncture has created a tragedy like that of the Medusa. In this Greek myth, an originally lovely woman turns monstrous because of her foolish act of aspiring to be a goddess. We see a parallel between this classical myth and the transformations within womenâs studies. Facing the Medusa tragedy that has befallen the womenâs studies movement due to the hegemonic aspirations of its members is so frightening that to join its ranks or to consider taking on such a movement from within could prove death-dealing. The ultimate fear when facing the Medusa for womenâs studies scholars is that they might prove what their male detractors have been saying--that she was a monster all along
The plantâparasitic cyst nematode effector GLAND4 is a DNAâbinding protein
Cyst nematodes are plant pathogens that infect a wide range of economically important crops. One parasitic mechanism employed by cyst nematodes is the production and in planta delivery of effector proteins to modify plant cells and suppress defenses to favor parasitism. This study focused on GLAND4, an effector of Heterodera glycines and H. schachtii, the soybean and sugar beet cyst nematodes, respectively. We showed that GLAND4 is recognized by the plant cellular machinery and is transported to the plant nucleus, an organelle where little is known about plant nematode effector functions. We showed that GLAND4 has DNA-binding ability and repressed reporter gene expression in a plant transcriptional assay. One DNA-fragment that bound to GLAND4 was localized in an Arabidopsis chromosomal region associated with the promoters of two lipid transfer protein (LTP) genes. These LTPs have known defense functions and are downregulated in the nematode feeding site. When expressed in Arabidopsis, the presence of GLAND4 caused downregulation of the two LTP genes in question, which was associated also with increased susceptibility to the plant-pathogenic bacterium Pseudomonas syringae. Furthermore, overexpression of one of the LTP genes reduced plant susceptibility to H. schachtii and P. syringae, confirming that LTP repression likely suppresses plant defenses. This study made GLAND4 one of a small subset of characterized plant nematode nuclear effectors and identified GLAND4 as the first DNA-binding plantparasitic nematode effector
30 - Identifying the presence of âScn4a, Scn5a, â andâ Scn9a â in the Mammalian Clitoris
Between 40 and 50% of women report experiences of sexual dysfunction (SD). This includes an inability to achieve sexual arousal, experience sexual pleasure and/or achieve an orgasm. Though there is no evidence of SD interfering with the ability to conceive, the conditions impacts affected individuals quality of life. Of particular interest are the mechanisms involved in the process of female sexual arousal. SD is often viewed as a psychological condition and limited information is known about the biological underpinnings of this condition. The goal of our laboratory is to identify the role of voltage gated ion channels in the mammalian clitoris. These candidate genes are of interest based on studies examining patients with epilepsy reporting decreased ability to achieve sexual arousal after taking common antiepileptic drugs carbamazepine or phenytoin. These drugs function by blocking sodium current from voltage gated ion channels in excitable cells. This suggests that voltage gated sodium channels may be present in the clitoris, and thusly play a role in sexual function. In this project, we sought to identify if voltage gated ion channels commonly found in the peripheral nervous system where expressed in the mammalian clitoris. This includes Scn4a, Scn5a, and Scn9a. Utilizing a RT-PCR profiler assay for neuronal ion channels (Qiagen, inc), we examined the expression pattern of these transcripts in the C57B/6J mouse clitoris tissue. Expression patterns were then confirmed with single RT-PCR. Transcripts with a â„ 2 fold difference were considered significant. We found that Scn9a was expressed in this excitable tissue at significant levels, suggesting its role in arousal and the potential for therapeutic intervention
Nonaqueous Fluoride/Chloride Anion-Promoted Delamination of Layered Zeolite Precursors: Synthesis and Characterization of UCB-2
The delamination of layered zeolite precursor PREFER is demonstrated under mild nonaqueous conditions using a mixture of cetyltrimethylammonium bromide, tetrabutylammonium fluoride, and tetrabutylammonium chloride in N,N-dimethylformamide (DMF) as solvent. The delamination proceeds through a swollen material intermediate which is characterized using powder X-ray diffraction (PXRD). Subsequent addition of concentrated HCl at room temperature leads to synthesis of UCB-2 via delamination of the swollen PREFER material and is characterized using PXRD, transmission electron microscopy (TEM), and argon gas physisorption, which shows lack of microporosity in UCB-2. ^(29)Si magic angle spinning (MAS) NMR spectroscopy indicates lack of amorphization during delamination, as indicated by the entire absence of Q^2 resonances, and ^(27)Al MAS NMR spectroscopy shows exclusively tetrahedral aluminum in the framework following delamination. The delamination process requires both chloride and fluoride anions and is sensitive to solvent, working well in DMF. Experiments aimed at synthesizing UCB-2 using aqueous conditions previously used for UCB-1 synthesis leads to partial swelling and lack of delamination upon acidification. A similar lack of delamination is observed upon attempting synthesis of UCB-1 under conditions used for UCB-2 synthesis. The delamination of PREFER is reversible between delaminated and swollen states in the following manner. Treatment of as-made UCB-2 with the same reagents as used here for the swelling of PREFER causes the delaminated UCB-2 material to revert back to swollen PREFER. This causes the delaminated UCB-2 material to revert back to swollen PREFER. Altogether, these results highlight delamination as the reverse of zeolite synthesis and demonstrate the crucial role of noncovalent self-assembly involving the zeolitic framework and cations/anions/structure-directing agent and solvent during the delamination process
- âŠ