Coexistence of excited polarons and metastable delocalized states in photo-induced metals

We study how polaronic states form as a function of time due to strong electron-phonon coupling, starting from a hot electron distribution which is representative of a photo-induced metallic state immediately after laser excitation. For this purpose we provide the exact solution of the single-electron Holstein model within nonequilibrium dynamical mean-field theory. In particular, this allows us to reveal key features of the transient metallic state in the numerically most challenging regime, the adiabatic regime, in which phonon frequencies are smaller than the electronic bandwidth: Initial coherent phonon oscillations are strongly damped, leaving the system in a mixture of excited polaron states and metastable delocalized states. We compute the time-resolved photoemission spectrum, which allows to disentangle two contributions. The existence of long-lived delocalized states suggest ways to externally control transient properties of photo-doped metals.Comment: 14 pages, 7 figure

Fund Managers Adding Values? Measuring Performance without Benchmark – A Study of Indian Mutual Fund Schemes

This paper calculates the Portfolio Change Measure (PCM) developed by Grinblatt and Titman for a sample of 744 equity schemes of Indian mutual funds over a minimum period of more than 2 years and less than 11 years. PCM, based on holding of assets, is a measure which is free from ‘benchmark’ biases arising out of usage of a ‘benchmark’ portfolio. So by using PCM as a measure, this paper, without using any benchmark, attempts to assess whether the selected mutual fund managers were able to add value and exhibit superior skills on the average and thus making a case for active fund management over a passive buy and hold strategy. Using the monthly holding statement of each individual scheme’s portfolio, rolling PCM has been calculated on a monthly basis with a rolling window of one year. The results of our analysis, supported by robustness checks, which includes time periods of pre-and post-Global Financial Crisis, shows strong evidence of active fund management adding value in the stock selection and hence in return generating process, thus justifying the possession of superior skill or superior information of fund managers at an aggregate level. Finally, using Quantile Regression we identify some characteristics of the scheme like scheme size and ownership category, which influence PCM significantly

The Impact of Competitive Strategies, and Strategic Human Resource Management on Firm Performance of Palestine

This paper examines the impact of competitive strategies and strategic Human Resource Management on Firm Performance of Palestine from various critical perspectives. Rapid environmental changes, competition to provide innovative products and services, changing customer and investor demands and globalization have become the standard backdrop for firms. Sustained competitive advantage could be generated from a firm’s human capital by designing strategic human resource management to diagnose a firm’s strategic needs which is required to implement a competitive strategy and achieve operational goals. Effective human resource management strategy systematically organizes all individual human resource management measures to directly influence employee attitude and behavior in a way that leads business to achieve its competitive strategy. The researcher has selected corporate and non-corporate firms as well as small and Medium Corporation were chosen in different areas of Palestine (south, north, and middle) 106 respondents selected from 45 firms across the three zones of Palestine. The general objective of the study is to investigate the place of Strategic Human Resource Management in improving corporate performance among mentioned firms in Palestine. The study used descriptive statistics (frequencies, means and percentages) to answer the three research questions posed for the study. The Spearman Rank Correlation Coefficient was used to test the three hypotheses that guided the study. The final results showed that there is a strong positive correlation between strategic HRM and performance level of competition in the firms. It was also concluded that SHRM is an important and indispensable tool for any organizations performance and for any organization that wants to gain competitive advantage over others. Finally, this article develops a conceptual framework that explains the relationship between strategic human resource management, competitive strategies and firm Performance

Protection of all nondefective twofold degeneracies by antiunitary symmetries in non-Hermitian systems

Non-Hermitian degeneracies are classified as defective exceptional points (EPs) and nondefective de- generacies. While in defective EPs, both eigenvalues and eigenvectors coalesce, nondefective degeneracies are characterized merely by the emergence of degenerate eigenvalues. It is also known that all degeneracies are either symmetryprotected or accidental. In this paper, I prove that antiunitary symmetries protect all nondefective twofold degeneracies. By developing a 2D non-Hermitian tight-binding model, I have demonstrated that these symmetries comprise various symmetry operations, such as discrete or spatial point-group symmetries and Wick’s rotation in the non-Hermitian parameter space. Introducing these composite symmetries, I present the protection of nondefective degeneracies in various parameter regimes of my model. This work paves the way to stabilizing nondefective degeneracies and offers a new perspective on understanding non-Hermitian band crossings

The multiplier for the weak McShane integral

summary:The multiplier for the weak McShane integral which has been introduced by M. Saadoune and R. Sayyad (2014) is characterized

“We Really are Seeing Racism in the Hospitals”: Racism and Doula Care

Introduction: Poor birth outcomes are more prevalent for Black birthing people and their babies. Strong evidence shows that doula care, during labor and delivery, improves maternal and child health outcomes. Yet little is documented about racial differences, discrimination, and equity in doula care. Methods: Between November 2020 and January 2021, 17 surveys and in-depth interviews were conducted with doulas in Georgia as part of the community-based participatory Georgia Doula Study, co-led by Healthy Mothers, Healthy Babies Coalition of Georgia and academic researchers. The study objective was to describe the challenges and facilitators of providing doula care in Georgia. In the fall of 2021, additional measures on racism and discrimination in doula care were added to the survey and interview guide and previous participants were re-contacted. Results: Doula participants were diverse in age (41% 25-35, 35% 36-45, and 24% 46+) and race/ethnicity (53% white, 41% Black, 6% Latinx). Six of the seven (86%) Black doulas reported that more than 85% of their clientele is Black, while all of the eight white doulas reported that 50% or less of their clientele is Black. Three (18%) of the doulas indicated more than 10% of their clientele is Latinx, while only two (12%) indicated more than 10% of their clientele is Asian-American or Pacific Islander. Discrimination scores were 51.5 for Black doulas (standard deviation 7.55) 46.7 for white doulas (standard deviation 7.48). Doulas noted that the alarming maternal mortality rate for Black women and not always being listened to causes Black clients to be less trusting of medical staff, leaving them in need of advocates. Black doulas were passionate about serving and advocating with Black clients. Doulas also described how language and cultural barriers, particularly for Asian and Latinx birthing people, reduce clients’ ability to advocate for themselves, increasing the need for doulas. Conclusion: Black doulas are an essential tool for improving birth outcomes for Black women. Increasing access to doula care for Asian and Latinx communities could address language and cultural barriers that can negatively impact their maternal and child health outcomes

Importance of Social Media in Business Firm in Palestine & its Effects

Social media has provided new opportunities to businesses to engage customers through social interaction while creating leads and generating sales. No study has been conducted to identify the importance of social media and how social media has affected the marketing strategies of business firms in Palestine. 80 social media marketing experts were surveyed through a closed ended questionnaire in Palestine to find out the impact of social media on customer relationship building and sale volume of the businesses firms. Through regression and Pearson Correlation analysis, it is found that type of social media has insignificant correlation with social media for network building (r = .010), to attract potential customers (r = .003), and to engage customers (r = .069), whereas it has significant positive correlation with social media to communicate with customers (r = .104). Similarly, type of social media has a significantly positive correlation with the variables i.e. high sale (r = .215) and high rate of return on investment (r = .180)

Role of Myosin II and Arp 2/3 in the motility and force generation of Neuronal Growth Cones

Differentiating neurons have to find chemical cues to form the correct synaptic connections with the other neurons so that they can create a functional neuronal network. During their development differentiating neurons project neurites, at the distal part of which there is a growth cone (GCs). The growth cone has highly motile structures, referred as lamellipodia and filopodia. Lamellipodia and filopodia sense the environment and process the mechanical and chemical stimulus and also exert forces. During my work for the completion of my PhD thesis, I used Optical Tweezers, video imaging and immunocytochemistry to quantify the motility and the force exerted by lamellipodia and filopodia from Dorsal Ganglion (DRG) neurons. I have also precisely quantified the role of some proteins and signaling pathways which regulate the motility of the DRG GCs. The first part of my results entitled, \u201cThe role of myosin-II in force generation of DRG filopodia and lamellipodia\u201d, characterizes the role of Myosin II in growth cone dynamics. Myosin II has been shown to control the retrograde flow of actin polymers, to be involved in the orchestration of actin and microtubules (MTs) dynamics and to possess contractile activity. GCs advance due to combined effects of the adhesion of lamellipodia and filopodia on the substrate and the contractile activity of Myosin II. Therefore, I probed the functional role of Myosin II on GCs dynamics by using its specific inhibitor, Blebbistatin. I show that the force exerted by lamellipodia decreased but surprisingly the force exerted by filopodia increased upon treatment with Blebbistatin. Moreover I show that the well organized and distributed structures of lamellipodia and filopodia of the GCs depend on the activity of Myosin II and confirmed the coupling between actin and microtubule dynamics. The next chapter, \u201cThe role of Rac1 in force generation of DRG neurons\u201d, describes the function of Rac1 and its downstream effector Arp2/3 in lamellipodia and filopodia formation and dynamics. It is well known that Rac1 Rho-GTPase acts as a switch between GTP bound active state and GDP bound inactive state. I observed that GCs retract following partial inhibition of Arp2/3 but recover their usual motility within 5-10 minutes. I found that this recovery is caused by the activation of Rac1. This indicates that Rac1 acts as switch and activates upon Arp2/3 inhibition, possibly through integrin pathways. I also confirmed that the activity of Arp2/3 not only regulates the formation of lamellipodia but also controls the dynamics and formation of filopodia

Evolutionary Search Techniques with Strong Heuristics for Multi-Objective Feature Selection in Software Product Lines

Software design is a process of trading off competing objectives. If the user objective space is rich, then we should use optimizers that can fully exploit that richness. For example, this study configures software product lines (expressed as feature models) using various search-based software engineering methods. Our main result is that as we increase the number of optimization objectives, the methods in widespread use (e.g. NSGA-II, SPEA2) perform much worse than IBEA (Indicator-Based Evolutionary Algorithm). IBEA works best since it makes most use of user preference knowledge. Hence it does better on the standard measures (hypervolume and spread) but it also generates far more products with 0 violations of domain constraints. We also present significant improvements to IBEA\u27s performance by employing three strong heuristic techniques that we call PUSH, PULL, and seeding. The PUSH technique forces the evolutionary search to respect certain rules and dependencies defined by the feature models, while the PULL technique gives higher weight to constraint satisfaction as an optimization objective and thus achieves a higher percentage of fully-compliant configurations within shorter runtimes. The seeding technique helps in guiding very large feature models to correct configurations very early in the optimization process. Our conclusion is that the methods we apply in search-based software engineering need to be carefully chosen, particularly when studying complex decision spaces with many optimization objectives. Also, we conclude that search methods must be customized to fit the problem at hand. Specifically, the evolutionary search must respect domain constraints