Lingering Questions Research Articles

Alcohol effects on embryonal bone growth

Background:The possible teratogenic and lethal potencies of ethanol on the developing foetal bones especially when ingested during pregnancy is now well established; but the actual mechanisms of these actions are yet elusive and this had since stimulated unending interests and numerous researches particularly in the field of teratology. Are there yet any other possible mediators / agents to be implicated in the potentiation of ethanol toxicity? Are they existing or would there be possible solutions for assaults of alcohol abuse? Methods: A retrospective and contemporary literature compilation was done in an attempt to further explore this subject and bring out more detailed information useful to answering these and other such lingering questions. Results: The incidence of congenital bone malformations associated with maternal consumption of ethanol during conception are now recognised to be due to its toxic effects on the developing tissues and impairment of normal cellular activities particularly by depriving them of essential vitamins such as folic acid, a useful precursor for the synthesis of proteins and DNA. Conclusion: This is a situation where the most successful preventive measures could possibly be instituted, with folic acid supplementation, to alleviate ethanol toxicity, if total abstinence is not possible. Nigerian Journal of Surgical Research Vol. 7(1&2) 2005: 152-158

Cell‐cycle regulation and mammalian gametogenesis: A lesson from the unexpected

The progression of mammalian gametogenesis requires a precise balance between cell-cycle activities and elimination of defective gametogenic cells to ensure the perpetuation of species. Both spermatogonia and oogonia are stem cell populations committed to meiosis with the aim of generating haploid gametes for fertilization. At puberty, mitotically dividing spermatogonial cell cohorts maintain the ability of cell renewal and occupy niches in the seminiferous tubule. In contrast, mitotically dividing oogonial cell cohorts produced in the fetal ovary, are exclusively committed to meiosis and produce primordial follicles housing a primary oocyte surrounded by somatic follicular cells. A consistent physiological event during mammalian gametogenesis is the disposal of spermatogenic cells by apoptosis and ovarian follicles by atresia. Cyclin-dependent kinases (Cdks) and their cyclin partners coordinate the activities of the cell cycle. An additional cell-cycle regulatory component is the centrosome. The centrosome harbors regulatory proteins controlling the normal progression of the cell cycle. Changes in individual centrosome proteins can lead to cell-cycle arrest and a decrease in the genomic protective function of p53 that promotes apoptosis. Disruption of cyclin A1, Cdk2, and Cdk4 expression in transgenic mice results in infertility and gonadal atrophy. Cdk-cyclin complexes interact with regulatory proteins, which may fine-tune the activities of the complex. One of the many regulatory proteins is p12, a 115 amino acid growth suppressor polypeptide designated p12(CDK2AP1), partner of Cdk2 and with binding affinity to DNA polymerase alpha/primase. Overexpression of p12 is associated with testicular and ovarian atrophy without affecting fertility. Ectopic expression of p12 was driven by the keratin 14 promoter. Keratin 14 is the pairing partner of keratin 5 and both keratins are expressed in testis. The efficiency of keratin promoters in driving ectopic gonadal gene expression, the association of gonadal atrophy with the ectopic expression of a Cdk2 regulatory protein and the centrosome, as a reservoir of cell-cycle regulatory proteins, open new experimental opportunities to address still lingering questions concerning cell differentiation and division during mammalian gametogenesis.

Response

Response Stephanie Y. Mitchem (bio) I am grateful to Monica Coleman for her article, because she raises the lingering questions of black women's academic and intellectual identities. Her questions bring me to moments of reflection and analysis, including a closer look at myself, my professional path, and the "state" of academe. What follows is a theological reflection inspired by Coleman's question, "Must I be womanist?" I did not come to academe by way of my initial undergraduate experiences. In fact, in the 1970s I dropped out of a public college in Michigan that had improved racism to a fine art. I moved away from the academic and was committed to leading an activist life, sometimes in church settings, sometimes not. At different times, I was involved in providing counseling and community education. Slowly, I moved to the administrative side, such as managing grants and performing political advocacy. The time came, however, when I went back to academe. It was, now that I think about it, a natural progression. How could I integrate different areas of my life while continuing to grow? What had I learned from my activist life? How could I lend a greater weight of authority to my words? [End Page 123] Yet, I did not return to the academy expecting a perfect world, one without conflict. Further, with my activist mind-set, my eyes were open to see areas of contention and weakness and to act as an agent of change when possible. So I am baffled when I read Coleman's words, as a representative of third-wave feminists, with questions about the status quo and the efficiency of their predecessors. What did she and third wavers expect to find in the academic world? But I get ahead of myself here. There were points throughout my returning undergraduate and later master's-level studies, in the 1980s, when I encountered professors who did not know of any black women who wrote in any religious field. But they knew of many white American women writing about everything. I read many of these white women's books with dismay when the words did not wrap around my black, working-class woman's experiences, often resonating with the question attributed to Sojourner Truth: "Ain't I a woman?" The professors' ignorance shaped my future studies, lending a new passion to my desire to end, specifi cally, the silencing of black women on too many levels of academe and, generally, the rejection of black scholarship's legitimacy. During my doctoral work, I was able to blend religious studies with anthropology, ethnography, American history, and ethics in order to explore the religiosity of black women. Womanist thought was the arena to which I gravitated with my disciplinary base in theology. Womanist thought was also the arena in which my activist mind could identify continuing ways to engage other black women. Yet when I work with black women in other disciplines—particularly history, sociology, or anthropology—I use the term "black feminist" to describe my approach. This is strategic, as the black women scholars in these disciplines understand their work under the name black feminism. These black feminists are the ones from whom I learn. I do not fi nd such usage of different terms a form of doublethink; I do not experience any kind of cognitive dissonance. Instead, I understand womanist and black feminist thought to fall along a continuum following the ideas of cultural theorist and black feminist Joy James: "To some degree then, we can distinguish between a conventional feminism embraceable by all progressive women, including those who happen to be black, and a black feminism or womanism, one particular to women of African descent."1 James's view defi nes feminism, black feminism, and womanism in nonconflictual terms. It is not necessary, with such an understanding, to anguish over whether one is black feminist or womanist or generic feminist. Frankly, ranges of intellectual stances are found within each grouping. This diversity of women's voices is welcome to me; I am afraid of any group of people parroting the same phrases with the same infl ections. (The idea that such a firm unanimity can exist reminds...

State Postsecondary Policy Innovation: Politics, Competition, and the Interstate Migration of Policy Ideas

Lingering questions about the effects of postsecondary governance structure on the policy-adoption behavior of state governments have assumed new significance in light of a recent wave of financing and accountability policy innovation in the postsecondary-education sector. Using longitudinal analysis, this study tests the effects of postsecondary governance structure, state socioeconomic and political characteristics, and interstate "diffusion" dynamics on state policy innovation patterns in the postsecondary-education sector between 1981 and 1998. Governance arrangements showed only a weak relationship to innovation patterns, but legislative party control and interstate diffusion had a strong effect upon the adoption of new postsecondary financing policies.

Research hurdles complicating the analysis of infertility treatment and child health.

Research aimed at the empirical evaluation of infertility treatment including assisted reproductive technologies (ART) on child health and development is hampered by investigators' inability to methodologically separate possible treatment effects from underlying fecundity impairments. While the literature continues to identify ART as a risk factor for many child health outcomes, less attention has been paid to the methodologic rigor needed to answer this question. We identify aspects of fecundity and the nuances of medical practice that need to be considered and captured when designing epidemiologic investigations aimed at assessing ART and child health. These include: (i) the use of prospective study designs in which the unit of analysis (cycle versus individual versus couple) is defined; (ii) data collection on relevant time-varying covariates at, before and during treatment; and (iii) the use of statistical techniques appropriate for hierarchical data and correlated exposures. While none of these issues in and by itself is unique to ART research, attention to these issues has been lacking in much of the published research limiting our ability to evaluate health consequences for children. Longitudinal studies of children conceived with ART will benefit from attention to these issues and, hopefully, produce answers to lingering questions about safety.

New Technology Briefing: Kiosks — Hype or hope?

New marketing technologies allow marketers unprecedented access to the buying habits and behaviours of their customers. But hundreds of targeted television channels, websites, retail stores and magazines make it increasingly difficult for marketers actually to get their customers' undivided attention. As channels and points of influence increase, marketers must work harder to have consistent messages and experiences while striving to collect as much accurate data through as many points of contact as possible. Although kiosks hope to decrease operational costs through self-service, they also offer yet another contact point for marketers and their customers. Even as costs for display technologies and networks are falling, there are still lingering questions about user adoption and return on investment. This paper looks at what kiosks are, how they work and their uses, problems from the past and what we can hope to see from them in future.

Is a transactions tax an effective means to stabilize the foreign exchange market

The desirability of a transactions tax in the foreign exchange market, or Tobin tax, depends on whether the tax deters short-term, destabilizing trade. While supporters claim that the tax would be a deterrent for short-term capital flows, critics contend that the deterrent capability of the tax would be limited. This paper attempts to resolve some lingering questions about the arithmetic of a transactions tax, and concludes that a tax would raise the required return from trade for any time horizon, and thus deter all trades driven by small expected capital gains (i.e., smaller than the square of one plus the tax rate), and not necessarily those driven by a short horizon of the investor. The paper then explores the consequences of this result on the effectiveness of the tax within competing paradigms and concludes that a Tobin tax is not likely to be an effective means to reach the declared objectives. JEL Codes: F31, H87 Keywords: Foreign Exchange

Thermal conductivity inB- andC- phases ofUPt3

Although the superconductivity in UPt_3 is one of the most well studied, there are still lingering questions about the nodal directions in the B and C phase in the presence of a magnetic field. Limiting ourselves to the low temperature regime (T<<Delta(0)), we study the magnetothermal conductivity with in semiclassical approximation using Volovik's approach. The angular dependence of the magnetothermal conductivity for an arbitrary field direction should clarify the nodal structure in UPt_3.

APP processing enzymes (secretases) as therapeutic targets: insights from the use of transgenics (Tgs) and transfected cells.

Secretases degrade amyloid precursor protein (APP) releasing fragments (beta-peptides A beta, A beta x) that assemble to form hallmark extracellular deposits in Alzheimer's disease (AD) correlating with disease severity. As such, secretases supply targets for therapeutic intervention and form the focus of this overview. Progress in elucidating secretases and their modes of catalysis come from exploiting the use of transgenics or transfected cells. In addition to A beta x, secretases also release C-terminal fragments with putative signaling properties (amyloid intracellular domain, AICD) similar in concept to those available for conversion of the Notch-r to release the nuclear transactivator NICD. The review considers lingering questions on APP fragmentation by secretase action, ancillary proteins such as presenilins (PS1/2), nicastrin, XII, or proteases (caspases), and the influence of familial mutations (mAPP, mPS) in terms of fibrillogenesis.

Computer Simulations of Local Concentration Variations in Miscible Polymer Blends

The dynamics of the two different components of thermodynamically miscible polymer blends can have very different temperature dependences (“thermorheologically complex”) in some cases, while in others the two components behave more in agreement with intuition and have similar temperature dependences. The presence of spatial concentration variations over very local length scales (typically nanometers in size) caused by a combination of thermodynamic factors and chain connectivity effects is one explanation for thermorheological complexity. While several theories have been presented to rationalize this rich variety of rheological behavior, there remain lingering questions of the relative importance of system thermodynamics and chain connectivity effects in determining concentration variations over such small spatial domains. We critically investigate these issues using lattice Monte Carlo simulations on model binary blends. Our simulations show that the distribution of concentrations encountered within a specified control volume is indeed Gaussian with widths that are in excellent agreement with the predictions of mean-field theory. However, these distributions are centered at compositions that are significantly enriched due to chain connectivity effects. These results provide an excellent basis for the development of microscopic theories for the dynamics of polymer blends.

Marking Religious and Ethnic Boundaries: Cases from the Ancient Golan Heights

In the aftermath of the 1967 “Six Days' War,” 254 ancient inscribed stones were found in forty-four towns and villages of the Golan Heights—241 in Greek, 12 in Hebrew or Aramaic, and 1 in Latin. These stones, along with numerous architectural fragments, served as the basis of the 1996 book by myself and Dan Urman, Jews, Pagans, and Christians in the Golan Heights—a study of settlement patterns of people of the three religions in this region in the early centuries of the common era.1 The area of the Golan heights, roughly the size of Rhode Island, was in antiquity a place of agriculture and, for the most part, small communities. Though historians of religions in the late Roman period have long been aware of the “quartering” of cities, and of the locations of particular religious groups in this or that section of urban areas, we have had little information concerning the ways in which Hellenes, Jews, and Christians took up residence in relation to each other in those rural settings featuring numerous towns and hamlets— most presumably too small to have “zones” for ethnic and religious groups. The surviving artifacts of a number of the Golan sites gave the opportunity for a case study. Part 1 of this article centers on evidence for the locations and possible interactions of members of these religious groups in the Golan from the third to the seventh centuries and entails a summary of findings in the earlier work, while part 2 takes up several lingering questions about religious identity and ways of “marking” it within Golan countryside communities. Both sections can be placed under a rubric of “boundary drawing and religion.”

Evidence for the Validity of PC-based Simulations in Studying Aircrew Coordination

Recently, advances in computer technology have allowed the use of PC-based simulations for a variety of aviation training and research purposes. One area in particular where PC-based simulations have been used extensively is the study of aircrew coordination. Yet, there have always been lingering questions about the validity of these simulations. Critics have argued that most PC-based simulations are derived from video games and that gaming cannot substitute for actual work tasks. Also, the low physical fidelity of these devices has been cited as a potential threat to validity. By reviewing a number of aircrew studies conducted over the past 10 years and by presenting new experimental results, this article provides evidence for the validity of using PC-based simulations. Additionally, this article provides a set of guidelines that can be used by practitioners to increase the validity of their simulations.

Comparison of Carbon Dioxide and Methane as Additives at Steamflood Conditions

Summary Heavy-oil production from a steamdrive may be improved by adding gases to reduce the steam requirement, to swell the oil, and to reduce oil viscosity. To help compare carbon dioxide (CO2) and methane (CH4), two of the most reasonable choices of gaseous additives, we measured the viscosity and density of a Lloydminster- type heavy oil when saturated with each gas at a single pressure at 25°, 80°, and 150°C. Our measurements were repeated in the presence of a water phase to address the lingering questions about the effect of water on this equilibrium, especially at 150°C. In addition to confirming trends identified by previous authors, the results showed that the benefit of dissolved CH4 diminishes much less rapidly with rising temperature than for CO2. By 150°C the differences in benefit are small, which indicates that CH4 could be a more economical choice than CO2 as a steam additive in many reservoirs. In addition, no effect of equilibrium water was detected.

Gender, voice, electronic communication and postmodern values

Living and living with the postmodern values of diversity, flexibility, voice, humanness, inspirational leadership, shared power, and global sensitivity can result in very different outcomes for organizational members. Discusses these potentially contradictory out‐comes. Presents the authors′ personal accounts and reactions to the postmodern production technologies which were used in the development of the article and the lingering questions which have resulted from this process. Implications of greater reliance on technology for diversity and voice are discussed.

Market Morality: Robert Nozick and the Question of Economic Justice

Abstract. The study of markets and market prices has been a central feature of economic inquiry since the 18th Century. There have always been lingering questions on the meaning of market prices. Most moderneconomists argue that there are no normative implications to price analysis. The disclaimers of some economists about normative judgments ring hollow in the light of their vigorous advocacy of free market solutions to economic and other problems. Either free market solutions are superior alternatives or they are not; one cannot have a value free analysis and an ideological advocacy at the same time. The philosopher, Robert Nozick, in Anarchy, State, and Utopia, clearly finds meaning in the market place. His entitlement theory is predicated upon free exchange of goods and productive services. The normative use of free markets in general and of Robert Nozick's formulation in particular, it is contended, are inconsistent, illogical, and unscientific.