Cdc42 Effector Protein 2 (XCEP2) is required for normal gastrulation and contributes to cellular adhesion in Xenopus laevis

BACKGROUND: Rho GTPases and their downstream effector proteins regulate a diverse array of cellular processes during embryonic development, including reorganization of cytoskeletal architecture, cell adhesion, and transcription. Changes in the activation state of Rho GTPases are converted into changes in cellular behavior by a diversity of effector proteins, which are activated in response to changes in the GTP binding state of Rho GTPases. In this study we characterize the expression and function of one such effector, XCEP2, that is present during gastrulation stages in Xenopus laevis. RESULTS: In a search for genes whose expression is regulated during early stages of embryonic development in Xenopus laevis, a gene encoding a Rho GTPase effector protein (Xenopus Cdc42 effector protein 2, or XCEP2) was isolated, and found to be highly homologous, but not identical, to a Xenopus sequence previously submitted to the Genbank database. These two gene sequences are likely pseudoalleles. XCEP2 mRNA is expressed at constant levels until mid- to late- gastrula stages, and then strongly down-regulated at late gastrula/early neurula stages. Injection of antisense morpholino oligonucleotides directed at one or both pseudoalleles resulted in a significant delay in blastopore closure and interfered with normal embryonic elongation, suggesting a role for XCEP2 in regulating gastrulation movements. The morpholino antisense effect could be rescued by co-injection with a morpholino-insensitive version of the XCEP2 mRNA. Antisense morpholino oligonucleotides were found to have no effect on mesodermal induction, suggesting that the observed effects were due to changes in the behavior of involuting cells, rather than alterations in their identity. XCEP2 antisense morpholino oligonucleotides were also observed to cause complete disaggregation of cells composing animal cap explants, suggesting a specific role of XCEP2 in maintenance or regulation of cell-cell adhesion in early embryos. This loss of cell adhesion could be rescued by co-injection with a morpholino-insensitive version of the XCEP2 mRNA. CONCLUSIONS: XCEP2 appears to be an essential component in the early developmental program in Xenopus laevis. XCEP2 is involved in maintenance of cell-cell adhesion, and as such may constitute a regulatory component that could help to balance the need for tissue integrity and plasticity during the dynamic cellular rearrangements of gastrulation

Carrot or Stick? The Shift from Voluntary to Mandatory Disclosure of Risk Factors

This study investigates risk factor disclosures under the voluntary, incentive-based disclosure regime provided by the safe harbor provision of the Private Securities Litigation Reform Act and the SEC’s subsequent disclosure mandate. Firms subject to greater litigation risk disclose more risk factors, update the language more from year-to-year, and use more readable language than firms with lower litigation risk. These differences in the quality of disclosure are pronounced in the voluntary disclosure regime, but converge following the SEC mandate. Consistent with these findings, the risk factor disclosures of high litigation risk firms are significantly more informative about systematic and idiosyncratic firm risk when disclosure is voluntary but not when disclosure is mandated. Overall, the results suggest that for some firms voluntary disclosure of risk factors is not a substitute for a regulatory mandate

Carrot or Stick? The Shift from Voluntary to Mandatory Disclosure of Risk Factors

This study investigates risk factor disclosures, examining both the voluntary, incentive-based disclosure regime provided by the safe harbor provision of the Private Securities Litigation Reform Act as well as the SEC\u27s subsequent mandate of these disclosures. Firms subject to greater litigation risk disclose more risk factors, update the language more from year to year, and use more readable language than firms with lower litigation risk. These differences in the quality of disclosure are pronounced in the voluntary disclosure regime, but converge following the SEC mandate as low-risk firms improved the quality of their risk factor disclosures. Consistent with these findings, the risk factor disclosures of high-litigation-risk firms are significantly more informative about systematic and idiosyncratic firm risk when disclosure is voluntary but not when disclosure is mandatory. Overall, the results suggest that for some firms voluntary disclosure of risk factors is not a substitute for a regulatory mandate

The Screening Effect of the Private Securities Litigation Reform Act

Prior research shows that the PSLRA increased the significance of merit-related factors, such as the presence of an accounting restatement or insider selling, in determining the incidence and outcomes of securities fraud class actions. (Johnson, Nelson, and Pritchard, 2007). This result, however, is consistent with two possible hypotheses. First, the PSLRA may have reduced solely the incidence of non-meritorious litigation. Second, the PSLRA may have changed the definition of merit, effectively precluding claims that would have survived and produced a settlement pre-PSLRA. This paper tests these alternative hypotheses. We find that pre-PSLRA claims that settled for nuisance value would be less likely to be filed under the PSLRA regime. We also find, however, that pre-PSLRA non-nuisance claims would be less likely to be filed post-PSLRA period. The latter result, which we refer to as the screening effect, is particularly pronounced for claims lacking obvious hard evidence indicia of fraud (an accounting restatement or an SEC investigation). This screening effect is stronger if the claims also lacked evidence of abnormal insider trading. By contrast, we find that pre-PSLRA claims with hard evidence or abnormal insider trading would be no less likely to be filed in the post-PSLRA period. We also examine the likelihood of settlement for pre-PSRLA claims if they had been filed in the post-PSLRA period, and find a similar screening effect for case outcomes. We conclude that Congress effectively changed the definition of merit in adopting the PSLRA, discouraging suits that would have produced a non-nuisance outcome prior to the law’s enactment

Merit Pay Incentive Plans and Faculty Motivation at Liberal Arts Colleges

This study examined faculty behavior under merit pay Plans at four liberal arts colleges to determine whether there was a relationship between faculty motivation (effort) and the degree to which institutional pay plans and individual expectancies conformed to Lawler's theory of the conditions necessary for an effective monetary incentive structure (Lawler 1971, 1981, 1990). These conditions are: 1) A perception that performance and merit awards are linked; 2) Monetary rewards are highly valued; 3) Award size is large enough to make an impact; and 4) Information about rewards are publicly disclosed. The study proposed the question: Is there an association between motivation levels among faculty subject to merit pay plans and the presence of the theory conditions, or do other factors relate to faculty motivation? Using questionnaires to faculty, statistical correlation techniques tested for associations between reported faculty behavior and Lawler's four theory conditions. Lawler's theory did not apply to this group of faculty. The reward size condition showed the expected positive association, however, contrary to theory hypothesis, the perception of the pay-performance link was negatively related. Of the faculty characteristics examined, faculty with higher salaries and those with tenure reported less willingness to give additional effort to most activities. The faculty had highly inaccurate perceptions of the actual merit payments awarded to others at their institutions. The perception of the strength of the pay-performance link indicated that faculty believe the determination of reward recipients is unpredictable with respect to one's performance. These faculty members valued monetary rewards, yet responses to merit pay in the form of greater effort was weak. The stronger response to merit pay by the faculty at the non-merit pay institution suggests that familiarity with a merit pay system in practice breeds a more skeptical attitude because it has not proven as equitable or fruitful in operation as the faculty expect in the abstract. The findings suggest a need to look more closely at the role of intrinsic rewards, the perceived pay-performance relationship factor, and the process of determining rewards

In re Silicon Graphics Inc.: Shareholder Wealth Effects Resulting from the Interpretation of the Private Securities Litigation Reform Act\u27s Pleading Standard

This Article presents an empirical study of changes in shareholder wealth resulting from the Ninth Circuit Court of Appeals decision in In re Silicon Graphics Inc. Securities Litigation, which interpreted the pleading provision established in the Private Securities Litigation Reform Act of 1995 (the Reform Act ). Congress passed the Reform Act as part of an ongoing effort to protect corporations from abusive suits alleging fraud by hindsight. In such suits, plaintiffs claimed that a sudden drop in a company\u27s stock price was evidence that the issuer and its management covered up the bad news that led to the price drop. The Reform Act discourages such suits by requiring complaints alleging fraud to state with particularity facts giving rise to a strong inference that the defendant acted with the required state of mind. Courts have interpreted the Reform Act\u27s pleading standard in diverse ways. The Ninth Circuit\u27s interpretation in Silicon Graphics is the most stringent, requiring plaintiffs to allege facts that would show the defendants were deliberately reckless in making the misrepresentation that gave rise to the fraud claim. This pleading standard allows courts to dismiss fraud suits at an early stage if the court deems they lack merit, but it also increases the risk courts will dismiss meritorious suits as well

The Screening Effect of the Private Securities Litigation Reform Act

Prior research shows that the Private Securities Litigation Reform Act (PSLRA) increased the significance of merit-related factors in determining the incidence and outcomes of securities fraud class actions (Johnson et al. 2007). We examine two possible explanations for this finding: the PSLRA may have reduced the incidence of nonmeritorious litigation, or it may have changed the definition of merit, effectively precluding claims that would have survived and produced a settlement pre-PSLRA. We find no evidence that pre-PSLRA claims that settled for nuisance value would be less likely to be filed under the PSLRA regime. There is evidence, however, that pre-PSLRA nonnuisance claims would be less likely to be filed under the PSLRA regime. The latter result, which we refer to as the screening effect, is particularly pronounced for claims lacking hard evidence of securities fraud or abnormal insider trading. We find only limited evidence of a similar screening effect for case outcomes

In re Silicon Graphics Inc.: Shareholder Wealth Effects Resulting from the Interpretation of the Private Securities Litigation Reform Act\u27s Pleading Standard

This Article presents an empirical study of changes in shareholder wealth resulting from the Ninth Circuit Court of Appeals decision in In re Silicon Graphics Inc. Securities Litigation, which interpreted the pleading provision established in the Private Securities Litigation Reform Act of 1995 (the Reform Act ). Congress passed the Reform Act as part of an ongoing effort to protect corporations from abusive suits alleging fraud by hindsight. In such suits, plaintiffs claimed that a sudden drop in a company\u27s stock price was evidence that the issuer and its management covered up the bad news that led to the price drop. The Reform Act discourages such suits by requiring complaints alleging fraud to state with particularity facts giving rise to a strong inference that the defendant acted with the required state of mind. Courts have interpreted the Reform Act\u27s pleading standard in diverse ways. The Ninth Circuit\u27s interpretation in Silicon Graphics is the most stringent, requiring plaintiffs to allege facts that would show the defendants were deliberately reckless in making the misrepresentation that gave rise to the fraud claim. This pleading standard allows courts to dismiss fraud suits at an early stage if the court deems they lack merit, but it also increases the risk courts will dismiss meritorious suits as well

Shareholder Wealth Effects of the Private Securities Litigation Reform Act of 1995

This paper investigates the reaction ofstock prices to enactment of the Private Securities LitigationReform Act of 1995 (PSLRA). Based on a sample of 489 high-technologyfirms, we find that the PSLRA was wealth-increasing, on average,and that the market reaction is more positive for firms at greatestrisk of being sued in a securities class action. However, wealso show that the PSLRA was less beneficial for firms likelyto be the subject of a meritorious lawsuit. Collectively, ourevidence implies that shareholders generally benefit from restrictionson private securities litigation, although these benefits aremitigated when other mechanisms for curbing fraudulent activityare inadequate.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47702/1/11142_2004_Article_269852.pd

Documentation of human rights abuses among Rohingya refugees from Myanmar

Background: Decades of persecution culminated in a statewide campaign of organized, systematic, and violent eviction of the Rohingya people by the Myanmar government beginning in August 2017. These attacks included the burning of homes and farms, beatings, shootings, sexual violence, summary executions, burying the dead in mass graves, and other atrocities. The Myanmar government has denied any responsibility. To document evidence of reported atrocities and identify patterns, we interviewed survivors, documented physical injuries, and assessed for consistency in their reports. Methods: We use purposive and snowball sampling to identify survivors residing in refugee camps in Bangladesh. Interviews and examinations were conducted by trained investigators with the assistance of interpreters based on the Istanbul Protocol - the international standard to investigate and document instances of torture and other cruel, inhuman, and degrading treatment. The goal was to assess whether the clinical findings corroborate survivors\u27 narratives and to identify emblematic patterns. Results: During four separate field visits between December 2017 and July 2018, we interviewed and where relevant, conducted physical examinations on a total of 114 refugees. The participants came from 36 villages in Northern Rakhine state; 36 (32%) were female, 26 (23%) were children. Testimonies described several patterns in the violence prior to their flight, including the organization of the attacks, the involvement of non-Rohingya civilians, the targeted and purposeful destruction of homes and eviction of Rohingya residents, and the denial of medical care. Physical findings included injuries from gunshots, blunt trauma, penetrating trauma such as slashings and mutilations, burns, and explosives and from sexual and gender-based violence. Conclusions: While each survivor\u27s experience was unique, similarities in the types and organization of attacks support allegations of a systematic, widespread, and premeditated campaign of forced displacement and violence. Physical findings were consistent with survivors\u27 narratives of violence and brutality. These findings warrant accountability for the Myanmar military per the Rome Statute of the International Criminal Court (ICC), which has jurisdiction to try individuals for serious international crimes, including crimes against humanity and genocide. Legal accountability for these crimes should be pursued along with medical and psychological care and rehabilitation to address the ongoing effects of violence, discrimination, and displacement