cssi/SciSciGPT-SciSciNet huggingface dataset:
Eelgrass community dominated by native omnivores in Bodega Bay, California, USA

Seagrass meadows are key nursery habitats for many important commercial and recreational fishes. This is due, in part, to high abundances of epifaunal invertebrate prey relative to other nearshore habitats. Despite this knowledge, baseline data for these invertebrate communities are scarce and limited in species-specific detail. Here we describe the results of a 16-mo survey of eelgrass, Zostera marina L., and its epifauna, conducted in Bodega Harbor, California, USA. In our study, we report several key ecological patterns: (1) this invertebrate assemblage comprises 39 identified taxa, mostly native detritivore-grazers; (2) this community is numerically dominated by three species, the polychaete worm Platynereis bicanaliculata (Baird, 1863), an undescribed porcellidiid copepod, and the native caprellid amphipod Caprella californica Stimpson, 1856; (3) both site and date significantly affected eelgrass and invertebrate abundances, (4) the effect of site upon invertebrate abundance is attributable to eelgrass habitat, namely leaf area and epiphyte load; and (5) our analysis suggests temperature explains the effect of date upon invertebrate abundance. The finding of a few dominant species concurs with surveys conducted elsewhere globally; however, the abundance of native species in Bodega Bay starkly contrasts with nearby San Francisco Bay, where eelgrass beds are dominated by introduced species. Furthermore, declines in eelgrass and epifauna coincide with the onset of "The Blob," an extreme warm water event that occurred along the California coastline. Our results support the importance of detritivore-grazers to seagrass ecology, as well as herald potential trophic effects of future extreme warm water events.
Using Xenopus Skin to Study Cilia Development and Function

Cilia are prevalent biological structures that are important for cell signaling and for generating fluid flow (or motility). Cilia are found throughout biology from single-celled organisms to vertebrates, and many model systems have been employed for their analysis. Here, we describe the use of Xenopus larval skin as a system for the study of ciliogenesis and ciliary function. In particular, we describe basic molecular and embryological manipulations and imaging techniques that have proven particularly useful for understanding the polarized beating of cilia and the generation of directed fluid flow (Werner & Mitchell, 2012). However, these same tools have the potential to benefit a large number of cilia-related biological questions.
CHAPTER 343 – T Lymphocytes

Signal transduction research in T lymphocytes has focused on identifying the receptors and intracellular proteins affecting specific signaling pathways. It has become clear that signaling machines in T cells differ in composition depending on the extracellular signal received and the requirements of the stimulated cell. The composition of an established signalosome could also change over time in order to fine-tune or alter effector signaling pathways. In the future, it will be important to determine the kinetics of assembly, the dynamics of composition, and the compartmentalization for all signalosomes induced in T cells, as well as to define the interactions between different signaling pathways. Future research will utilize functional genomics approaches to characterize the signalome—the entire complement of a T cell's signaling molecules and interactions in a temporal and spatial context.
Healing of corneal epithelial defects in plasminogen- and fibrinogen-deficient mice.

PURPOSE. The local deposition of fibrinogen and other plasma products from tears within corneal wounds and the expression of plasminogen activator by corneal epithelial cells suggest that the coagulation and fibrinolytic systems play an important role in corneal wound healing. The authors used mouse lines deficient in plasminogen (Pig), fibrinogen (Fib), or both to elucidate the roles of these key fibrinolytic and coagulation factors in the healing of corneal epithelial defects. METHODS. Mice were anesthetized, and corneal epithelial defects (3 mm) were created with a blade. The authors conducted histologic examination and immunohistochemical analysis on the healing of injured corneas. RESULTS. The corneal epithelial defects of wild-type mice with transparent corneas healed quickly in 7 days, whereas the healing of plasminogen-deficient mice was impaired and complicated by severe and persistent inflammatory responses, the formation of retrocorneal fibrin deposits, corneal cloudiness caused by scar-tissue formation, and often stromal neovascularization. To determine whether these defects in corneal wound repair were specifically related to an impediment in fibrinolysis, corneal wound healing was compared in mice with a combined deficiency in plasminogen and fibrinogen. The loss of fibrinogen in mice lacking plasminogen resulted in the restoration of normal healing with transparent corneas in 7 days, similar to that of wild-type mice. CONCLUSIONS. These results provide direct evidence that hemostatic factors play a crucial role in corneal wound repair despite the lack of local hemorrhage. Furthermore, they demonstrate that the essential role of plasmin in corneal would healing is fibrinolysis. It prevents the adverse inflammatory responses caused by prolonged fibrin and fibrinogen deposition in injured corneas. (Invest Ophthalmol Vis Sci. 1998;39:502-508)
Reconfigurable Microwave Photonic Spectral Shaper

A reconfigurable RF spectral shaper for dynamic wideband frequency component manipulation is experimentally demonstrated. Spectral functions including positive and negative slopes, low-pass, parabolic, inverted-parabolic functions, as well as triangular and saw-tooth functions have been achieved.
Climate versus geological controls on glacial meltwater micronutrient production in southern Greenland

Abstract Low concentrations of micronutrients in subarctic North Atlantic surface waters limit phytoplankton growth. Iron, phosphorous, and silicon are all potentially bio-limiting nutrients; iron is the most well documented in the subarctic North Atlantic. Manganese, nickel, copper and zinc are also essential trace metals for phytoplankton cell function. However, the spatial and temporal variability in the flux of these elements to the subarctic North Atlantic is undercharacterized. Here we show new data from the meltseason peak in 2013 indicating that glacial meltwater from the southern tip of Greenland has elevated dissolved major and trace metal concentrations compared to glacial meltwater draining shorter melt season glacial catchments to the north. Fe concentrations range from 0.13 to 6.97 μM, Zn from 4 to 95 μM, and Si from 4 to 36 μM, all higher than the depleted surface waters of the subarctic North Atlantic. Measured hydrochemical data modeled by PHREEQC indicates meltwater is undersaturated in pyrite and silicate phases but supersaturated with respect to oxyhydroxides, hematite and goethite, all phases that precipitate Fe as colloids, of which the nanoparticle phases should remain biologically available. The variability in geologic units between the sites indicates that subglacial lithology is a minor but not the dominant control on meltwater chemistry. The disparity in concentrations is directly correlated with climate, and an extended melt season, suggesting that future warming in Greenland will lead to increased trace element, and potential micronutrient, flux to the subarctic North Atlantic surface waters.
Detection of Viable Xanthomonas fragariae Cells in Strawberry Using Propidium Monoazide and Long-Amplicon Quantitative PCR.

Xanthomonas fragariae causes angular leaf spot in strawberry. The pathogen’s association with its host tissue is thought to be a condition for its survival. Consequently, transmission of the pathog...
Becoming White Teachers: Symbolic Interactions and Racializing the Raceless Norm in Predominantly Black Schools:

Under the banner of critical whiteness studies, scholars from across the disciplinary spectrum have spent the past several decades investigating whiteness and white racial identity, both in the Uni...
Individualized Multidirectional Variable Selection

In this article, we propose a heterogeneous modeling framework which achieves individual-wise feature selection and heterogeneous covariates’ effects subgrouping simultaneously. In contrast to conv...
Maternal regulation of SATB2 in osteo‐progeniters impairs skeletal development in offspring

Nutritional status during intrauterine and/or early postnatal life has substantial influence on adult offspring health. Along these lines, there is a growing body of evidence illustrating that high fat diet (HFD)-induced maternal obesity can regulate fetal bone development. Thus, we investigated the effects of maternal obesity on both fetal skeletal development and mechanisms linking maternal obesity to osteoblast differentiation in offspring. Embryonic osteogenic calvarial cells (EOCCs) were isolated from fetuses at gestational day 18.5 (E18.5) of HFD-induced obese rat dams. We observed impaired differentiation of EOCCs to mature osteoblasts from HFD obese dams. ChIP-seq-based genome-wide localization of the repressive histone mark H3K27me3 (mediated via the polycomb histone methyltransferase, enhancer of zeste homologue 2 [Ezh2]) showed that this phenotype was associated with increased enrichment of H3K27me3 on the gene of SATB2, a critical transcription factor required for osteoblast differentiation. Knockdown of Ezh2 in EOCCs and ST2 cells increased SATB2 expression; while Ezh2 overexpression in EOCCs and ST2 cells decreased SATB2 expression. These data were consistent with experimental results showing strong association between H3K27me3, Ezh2, and SATB2 in cells from rats and humans. We have further presented that SATB2 mRNA and protein expression were increased in bones, and increased trabecular bone mass from pre-osteoblast specific Ezh2 deletion (Ezh2flox/flox Osx-Cre+ cko) mice compared with those from control Cre+ mice. These findings indicate that maternal HFD-induced obesity may be associated with decreasing fetal pre-osteoblastic cell differentiation, under epigenetic control of SATB2 expression via Ezh2-dependent mechanisms.
Response rates in metastatic neuroendocrine tumors receiving peptide receptor radionuclide therapy and implications for future treatment strategies

Abstract Background Peptide receptor radionuclide therapy is a targeted therapy used to treat unresectable somatostatin receptor-positive neuroendocrine tumors. The objective of this study was to evaluate response rates among neuroendocrine tumors of different primaries and identify factors relevant to future treatment strategies. Methods We retrospectively reviewed patients who received peptide receptor radionuclide therapy for neuroendocrine tumors from 2018 to 2019 at our institution. Patients were assessed with computed tomography/magnetic resonance imaging and 68Ga-DOTATATE-positron emission tomography before and after 2 or 4 cycles of peptide receptor radionuclide therapy. Tumor response was evaluated by RECIST 1.1. Statistics included multinomial logistic regression models and Fisher exact test. Results Twenty-seven patients underwent 92 cycles of peptide receptor radionuclide therapy: pancreas (n = 11), small bowel (n = 7), and other (n = 9) neuroendocrine tumors. Overall, 30% (8 of 27) had partial response, 59% (16 of 27) stable disease, and 11% (3 of 27) progressed. Pancreatic neuroendocrine tumors responded differently from small bowel neuroendocrine tumors regardless of cycle number (P = .01). The majority of pancreatic neuroendocrine tumors (6 of 11) had partial response to peptide receptor radionuclide therapy, while all small bowel neuroendocrine tumors had stable disease. Pancreatic neuroendocrine tumors stable after 2 cycles were more likely to respond to additional cycles versus other neuroendocrine tumors (probability: 60% vs 11%). Conclusion Patients with unresectable advanced or metastatic pancreatic neuroendocrine tumors may benefit from a full course of peptide receptor radionuclide therapy, whereas other neuroendocrine tumors appear less likely to respond. Large prospective studies are needed to confirm these findings.
Who Sets the Limits of Educational Freedom

This article is a response to Matusov's argument for a student's right to define the limits of their own education. While I agree with Matusov's premise, I argue that his solution is framed as a dualism, which may undermine the dialogic principles of his call to students' educational freedoms. I propose that viewing students' educational freedoms through Bakhtin's arhcitectonic self removes the dualism of Matusov's argument, and close by providing an example of the architectonic self in practice within the teacher-student relationship.
What to expect when everyone is expecting: Self-fulfilling expectations and asset-pricing puzzles

Abstract We study an economy without bubbles in which expectations about future discount rates can become self-fulfilling because asset valuations redistribute wealth across different investor cohorts. For such redistribution to take place, the wealth of arriving and existing cohorts must react differently to discount rates, and in addition only the existing agents are marginal in financial markets. The self-fulfilling nature of discount rate expectations means that the economy can address several well-documented empirical asset-pricing facts (excessive volatility, return predictability, low interest rate level and volatility), while all real quantities (aggregate consumption and dividend growth) are smooth.
Electroanalytical Measurement of Interphase Formation at a Li Metal–Solid Electrolyte Interface

The interphase between Li metal and solid electrolytes dictates performance in Li metal batteries. For the solid electrolyte Lipon, we electroanalytically measure a capacity loss of 1.03 ± 0.16 μAh...
p53 Activates the Long Noncoding RNA Pvt1b to Inhibit Myc and Suppress Tumorigenesis

The p53 pathway is a key tumor suppressor mechanism that stalls cell cycle progression in response to stress. It has been proposed that p53 suppresses proliferation in part by downregulating the Myc oncogene but the mechanism has remained unclear. Here, we show that p53 directly represses Myc through a long noncoding RNA expressed from the Pvt1 locus. Pvt1b, a p53-dependent RNA isoform, is rapidly induced upon genotoxic and oncogenic stress and accumulates at its site of transcription in foci that exhibit properties of liquid-phase condensates. Pvt1b uses long-range chromatin interactions between Pvt1b and Myc to locally suppress Myc in an RNA-dependent manner. Loss of p53-dependent Pvt1b induction leads to increased cellular proliferation in vitro and enhanced tumor growth in a mouse model of lung adenocarcinoma in vivo. We propose that Pvt1b-mediated Myc repression contributes to the p53 tumor suppressive network to limit cancer growth.
Rational Action and Systemic Response: Using Time to Integrate Subjective and Objective Probabilities

Macro theories explore the properties of an economic system in its entirety, in contrast to the focus of micro theories on parts of that system. Where most macro theories reduce an economy to a representative agent, we follow Wagner (2012, 2020) in treating a macro economy as an ecology of plans. An ecology of plans contains two distinct analytical objects: the ecology as an entirety and the individual entities that constitute that ecology. To reduce the ecology to a representative or average agent is to create a category mistake by giving the ecology the property of rationality that it cannot possibly have. To avoid this mistake, we work with both subjective and objective probability concepts. Individual action is set within the purview of a theory of subjective probability. The ecological system is treated as a mechanism that can be described in terms of objective probability. There is, moreover, a significant interval of time that separates the initiation of individual plans from the subsequent market evaluation of those plans.
Heterogeneous Expression of Nuclear Encoded Mitochondrial Genes Distinguishes Inhibitory and Excitatory Neurons.

Mitochondrial composition varies by organ and their constituent cell types. This mitochondrial diversity likely determines variations in mitochondrial function. However, the heterogeneity of mitochondria in the brain remains underexplored despite the large diversity of cell types in neuronal tissue. Here, we used molecular systems biology tools to address whether mitochondrial composition varies by brain region and neuronal cell type in mice. We reasoned that proteomics and transcriptomics of microdissected brain regions combined with analysis of single cell mRNA sequencing could reveal the extent of mitochondrial compositional diversity. We selected nuclear encoded gene products forming complexes of fixed stoichiometry, such as the respiratory chain complexes and the mitochondrial ribosome, as well as molecules likely to perform their function as monomers, such as the family of SLC25 transporters. We found that the proteome encompassing these nuclear-encoded mitochondrial genes and obtained from microdissected brain tissue segregated the hippocampus, striatum, and cortex from each other. Nuclear-encoded mitochondrial transcripts could only segregate cell types and brain regions when the analysis was performed at the single cell level. In fact, single cell mitochondrial transcriptomes were able to distinguish glutamatergic and distinct types of GABAergic neurons from one another. Within these cell categories, unique SLC25A transporters were able to identify distinct cell subpopulations. Our results demonstrate heterogeneous mitochondrial composition across brain regions and cell types. We postulate that mitochondrial heterogeneity influences regional and cell type specific mechanisms in health and disease. Significance Statement Mitochondria are important organelles for maintaining brain health. The composition of proteins making up mitochondria is essential for their function. Disturbances to mitochondria are thought to contribute to neurodegeneration and neurodevelopmental disorders. These conditions typically affect specific brain regions or cell types. Despite the link between mitochondria and diseases with distinct anatomical and cellular patterns, how mitochondrial composition varies across brain regions and cell types remains poorly explored. Here, we analyze mitochondrial composition in different brain regions and cell types in adult mice, showing composition differs by region and cell lineage. Our work provides a resource of genes enriched in certain cell types or regions that improves our understanding of how mitochondrial composition influences brain function in health and disease.
Expanding the Lens: How SERT Therapists Develop Interventions that Address the Larger Context

Though many scholars have contributed to theories about how larger social contexts such as culture, gender, race, sexuality and religion impact people’s identities and approaches to intimate relationships, there is little in the literature to guide how to apply these theories into practice with couples. We summarize our grounded theory research on what informs therapists as they apply Socio-Emotional Relationship Therapy (SERT) to develop contextual, critically conscious interventions. Our analysis identified an organizing focus around addressing goals related to power: (1) identifying the power imbalances, (2) disrupting the flow of power, and (3) generating an alternative experience of shared power. These were informed by three important sources of information: (1) a contextual lens or theory, (2) the client’s experiences of sociocultural context, and (3) the therapist’s experiences of sociocultural context, as well as the value of peer consultation. We illustrate these processes through case examples and share personal reflections on how this grounded theory model now impacts our clinical work.
DD35: 1 Kranker + 1 Kranker = 3 Gesunde? Über Synergieverlust (März 2007)

Synergie bedeutet Zusammenwirken. Okonomen sagen, durch Zusammenfugen entstehe ein Synergiegewinn. Sie wollen folglich Fusionen. Aber Zusammenfugen bedeutet noch nicht Zusammenwirken. Das kostet unendlich viel Muhe. Wer das nicht versteht, sollte keine Verantwortung fur ein Ganzes tragen.
Identification of the cytochrome P450 enzymes involved in the N-demethylation of sildenafil

Aims To characterize the cytochrome P450 (CYP) enzymes responsible for the N-demethylation of sildenafil to its main metabolite, UK-103 320, to investigate the potential inhibitory effects of sildenafil on CYP enzymes and to evaluate the potential of selected drugs to affect sildenafil metabolism. Methods The metabolic pathways of sildenafil N-demethylation were studied using human liver microsomes, as well as microsomes expressing individual human CYP enzymes. Further studies to identify the individual enzymes were performed at 2.5 and 250 µm sildenafil, and employed a combination of chemical inhibition, correlation analysis, and metabolism by expressed recombinant CYP enzymes. In addition, the effect of sildenafil on the activity of the six major drug metabolizing enzymes was investigated. Results Sildenafil conversion was found to be mediated by at least two CYP enzymes, for which the mean kinetic parameters were Km1 = 6(±3 µm), Km2 = 81(±45 µm), Vmax1 = 22(±9 pmol) and Vmax2 = 138(±77 pmol) UK-103 320 formed min−1 mg−1. At 250 µm sildenafil, N-demethylation was primarily mediated through the low-affinity, high-Km enzyme (approximately 83%), whilst at 2.5 µm there was a greater role for the high-affinity, low-Km enzyme (approximately 61%). Ketoconazole strongly inhibited metabolism at both sildenafil concentrations and was the only significant inhibitor at 250 µm sildenafil. At the lower sildenafil concentration, sulphaphenazole and quinidine also inhibited formation of UK-103 320. Overall, 75% or more of the N-demethylation of sildenafil at any concentration is probably attributable to CYP3A4. These results were supported by experiments using expressed human CYP enzymes, in which only CYP3A4 and CYP2C9 exhibited substantial sildenafil N-demethylase activity (respective Km values of 221 µm and 27 µm). Sildenafil metabolism was inhibited by potent CYP3A4 inhibitors which are used clinically, but was found to be only a weak inhibitor of drug metabolizing enzymes itself, the strongest inhibition occurring against CYP2C9 (Ki = 80 µm). Conclusions Evidence is provided for CYP3A4 and to a lesser extent CYP2C9-mediated metabolism of sildenafil. There is the possibility that elevated plasma concentrations of sildenafil could occur with coadministration of known inhibitors of CYP2C9 or CYP3A4. Since peak plasma concentrations of clinical doses of sildenafil are only 200 ng ml−1 (∼0.4 µm) it is very unlikely that sildenafil will significantly alter the plasma concentration of other compounds metabolized by cytochrome P450 enzymes.
MSE behavior and centroid function of mth-order asymptotic /spl Sigma//spl Delta/ modulators

We say that a /spl Sigma//spl Delta/ modulator is asymptotic when all the zeros of its noise transfer function are located at z = 1 (zero frequency). It is usually understood from the classical white-noise model that the output of a stable mth-order asymptotic modulator includes a baseband mean squared error (MSE) that decays with the oversampling ratio R in O(1/R/sup 2m+1/). While this is indeed always true with constant inputs, we show numerically that with time-varying inputs, this result is in general not true, except in the particular case of the standard nonoverloading multibit multiloop configuration. The general MSE decay rate is in fact in O (1/R/sup 2m/) instead. We give mixed analytical and experimental explanations for this phenomenon thanks to the notion of "centroid function" of a modulator. We show that, besides the standard multibit multiloop configuration, it is actually possible to force an mth-order /spl Sigma//spl Delta/ modulator to yield an MSE decay rate of O(1/R/sup 2m+1/) with time-varying inputs, but this necessitates the introduction of a new species of EA modulators that include additional nonlinear memoryless operations.
Multiple functions of the origin recognition complex.

The origin recognition complex (ORC), a heteromeric six‐subunit protein, is a central component for eukaryotic DNA replication. The ORC binds to DNA at replication origin sites in an ATP‐dependent manner and serves as a scaffold for the assembly of other key initiation factors. Sequence rules for ORC–DNA binding appear to vary widely. In budding yeast the ORC recognizes specific ori elements, however, in higher eukaryotes origin site selection does not appear to depend on the specific DNA sequence. In metazoans, during cell cycle progression, one or more of the ORC subunits can be modified in such a way that ORC activity is inhibited until mitosis is complete and a nuclear membrane is assembled. In addition to its well‐documented role in the initiation of DNA replication, the ORC is also involved in other cell functions. Some of these activities directly link cell cycle progression with DNA replication, while other functions seem distinct from replication. The function of ORCs in the establishment of transcriptionally repressed regions is described for many species and may be a conserved feature common for both unicellular eukaryotes and metazoans. ORC subunits were found at centrosomes, at the cell membranes, at the cytokinesis furrows of dividing cells, as well as at the kinetochore. The exact mechanism of these localizations remains to be determined, however, latest results support the idea that ORC proteins participate in multiple aspects of the chromosome inheritance cycle. In this review, we discuss the participation of ORC proteins in various cell functions, in addition to the canonical role of ORC in initiating DNA replication.
Predictors of Nosocomial Bloodstream Infections in Older Adults

OBJECTIVES: To identify predictors and construct a prediction model for nosocomial bloodstream infection (BSI) in older adults. DESIGN: Retrospective case�control study. SETTING: Hospitals belonging to the Duke Infection Control Outreach Network. PARTICIPANTS: Patients age 65 and older with a nosocomial BSI and matched uninfected controls. MEASUREMENT: Multiple variables were captured and compared between groups. Independent predictors were identified using conditional logistic regression. A prediction model and score was constructed. RESULTS: Eight hundred thirty cases were compared with 830 controls. Eighty-one percent of nosocomial BSIs were catheter related (CRBSI). Methicillin-resistant Staphylococcus aureus (MRSA) was the most common pathogen isolated (23%). Independent predictors of nosocomial BSI in older adults were male sex, obesity, low McCabe score on admission, presence of a central line at admission, gastrostomy at admission, recent surgery, and urinary incontinence. A prediction model score greater than 11 (total possible score 23) was predictive of infection. CONCLUSION: MRSA is a common cause of CRBSI in older adults. Male sex, obesity, the presence of a central line, a gastrostomy tube, and urinary incontinence at the time of admission were independent predictors of BSI in hospitalized older adults. The prediction model constructed in this study should be validated prospectively in a different cohort.
The introduction of contraception in an urban public hospital.

Abstract This report describes the rapid expansion of contraceptive services as part of maternal health care in a large department (3,800 deliveries and 1,000 abortions per year). Several new approaches to the problem have been used and include: (a) IUCD (loop) insertion on the third or fourth postpartum day; (b) a “once-a-cycle” intramuscular injection of progestogen-estrogen mixture; (c) an oral sequential regimen with a new progestogen; (d) a “once-every-day” continuous oral regimen accomplished by adding five placebo tablets of different color to 20 combined progestogen-estrogen tablets. Patient acceptance and efficacy of these methods have been evaluated.
A comparative usability evaluation of traditional password managers

Proposed in response to the growing number of passwords users have to memorize, password managers allow to store one's credentials, either on a third-party server (online password manager), or on a portable device (portable password manager) such as a mobile phone or a USB key. In this paper, we present a comparative usability study of three popular password managers: an online manager (LastPass), a phone manager (KeePassMobile) and a USB manager (Roboform2Go). Our study provides valuable insights on average users' perception of security and usability of the three password management approaches. We find, contrary to our intuition, that users overall prefer the two portable managers over the online manager, despite the better usability of the latter. Also, surprisingly, our non-technical pool of users shows a strong inclination towards the phone manager. These findings can generally be credited to the fact that the users were not comfortable giving control of their passwords to an online entity and preferred to manage their passwords themselves on their own portable devices. Our results prompt the need for research on developing user-friendly and secure phone managers, owing to the ubiquity of mobile phones.
Analysis of Mitochondrial Dynamics and Functions Using Imaging Approaches

Mitochondria are organelles that have been primarily known as the powerhouse of the cell. However, recent advances in the field have revealed that mitochondria are also involved in many other cellular activities like lipid modifications, redox balance, calcium balance, and even controlled cell death. These multifunctional organelles are motile and highly dynamic in shapes and forms; the dynamism is brought about by the mitochondria's ability to undergo fission and fusion with each other. Therefore, it is very important to be able to image mitochondrial shape changes to relate to the variety of cellular functions these organelles have to accomplish. The protocols described here will enable researchers to perform steady-state and time-lapse imaging of mitochondria in live cells by using confocal microscopy. High-resolution three-dimensional imaging of mitochondria will not only be helpful in understanding mitochondrial structure in detail but it also could be used to analyze their structural relationships with other organelles in the cell. FRAP (fluorescence recovery after photobleaching) studies can be performed to understand mitochondrial dynamics or dynamics of any mitochondrial molecule within the organelle. The microirradiation assay can be performed to study functional continuity between mitochondria. A protocol for measuring mitochondrial potential has also been included in this unit. In conclusion, the protocols described here will aid the understanding of mitochondrial structure-function relationship.
Age-associated decline in ascorbic acid concentration, recycling, and biosynthesis in rat hepatocytes—reversal with (R)-α-lipoic acid supplementation

Ascorbic acid recycling from dehydroascorbic acid and biosynthesis from gulono-1,4-lactone were used as measures of cellular response capacity to increased oxidative stress induced by tert-butylhydroperoxide. The hepatic ascorbic acid concentration was 54% lower in cells from old rats when compared to cells isolated from young rats (P<0.0005). Freshly isolated hepatocytes from old rats exhibited a significantly decreased ascorbic acid recycling capacity in response to oxidative stress (P<0.005) compared to cells from young rats. Ascorbic acid synthesis in these cells from old animals was unaffected by various concentrations of tert-butylhydroperoxide, but amounted to only approximately half of the biosynthetic rate when compared to cells from young animals (P<0.001). Cells from young animals were not significantly affected by the tert-butylhydroperoxide treatments. The results demonstrate a declining ability with age to respond to increased oxidative stress. (R)-alpha-Lipoic acid, a mitochondrial coenzyme, is a powerful antioxidant. A two-week dietary supplementation of old animals with 0.5% (R)-alpha-lipoic acid prior to cell isolation almost completely reversed the age-associated effects on ascorbic acid concentration (P<0.0001), recycling (P<0.05) and biosynthesis after oxidative stress. These results provide further evidence for the potential of alpha-lipoic acid in treatment of diseases related to oxidative stress. Furthermore, the study extends the value of ascorbic acid as a biomarker of oxidative stress.
Cyanobacterial reuse of extracellular organic carbon in microbial mats

Cyanobacterial organic matter excretion is crucial to carbon cycling in many microbial communities, but the nature and bioavailability of this C depend on unknown physiological functions. Cyanobacteria-dominated hypersaline laminated mats are a useful model ecosystem for the study of C flow in complex communities, as they use photosynthesis to sustain a more or less closed system. Although such mats have a large C reservoir in the extracellular polymeric substances (EPSs), the production and degradation of organic carbon is not well defined. To identify extracellular processes in cyanobacterial mats, we examined mats collected from Elkhorn Slough (ES) at Monterey Bay, California, for glycosyl and protein composition of the EPS. We found a prevalence of simple glucose polysaccharides containing either α or β (1,4) linkages, indicating distinct sources of glucose with differing enzymatic accessibility. Using proteomics, we identified cyanobacterial extracellular enzymes, and also detected activities that indicate a capacity for EPS degradation. In a less complex system, we characterized the EPS of a cyanobacterial isolate from ES, ESFC-1, and found the extracellular composition of biofilms produced by this unicyanobacterial culture were similar to that of natural mats. By tracing isotopically labeled EPS into single cells of ESFC-1, we demonstrated rapid incorporation of extracellular-derived carbon. Taken together, these results indicate cyanobacteria reuse excess organic carbon, constituting a dynamic pool of extracellular resources in these mats.
Using or to Overcome Challenges in Implementing New Voting Technologies

In this article, we describe several operational challenges posed by the recent introduction of new voting technologies such as direct-recording electronic and optical-scan voting machines. These new voting technologies significantly complicate the operational and logistical complexity of administering elections. Poor management of the operations associated with these new technologies can negatively impact the voting process by leading to delays in voting, inequitable treatment of voters, and even voter disenfranchisement. Operations-research (OR) methods have proven extremely effective at meeting these operational and logistical challenges. We explain how OR methods can be used to improve the overall voting process when utilizing new voting technologies to increase social welfare. Keywords: voting; elections; queueing; simulation; optimization
Laparoscopic colposuspension for total vaginal prolapse

Abstract Objective: To present and evaluate a new technique of modified translaparoscopic colpopexy for total vaginal prolapse following hysterectomy as an alternative surgical mode of therapy to abdominal sacral suspension or transvaginal sacrospinous ligament vaginal vault suspension. A modest modification (Group II) of this author's initial surgical technique (Group I) and postoperative observations from 1989 to 1996 are presented. Methods: Twenty-seven patients with iatrogenic total vaginal prolapse subsequent to hysterectomy enrolled in this clinical study, which was conducted from September 1989 through February 1996. Posteriorly, vaginal apex was suspended to the deep layer of the uterosacral ligaments. The latero-posteriors vaginal cuff was suspended to the cardinal ligaments. Anteriorly, the vaginal vault was approximated to the pubocervical fascia. These procedures were performed in both groups retroperitoneally. Additionally, and only in Group II, retrpubically, at the mid-pelvic level, the pubocervical fascia and lateral superior vaginal sulci were suspended to the tendinous arch and to the fascia covering the muscles of the pelvic sidewall. This additional part of the operation constituted a modification of the initial translaparoscopic colpopexy (Group I). Results: In Group I, fifteen patients had good outcome of the operation. However, patient number 16 had a recurrent total vaginal vault prolapse within 6 months following the initial laparoscopic colpopexy. Preceding an initial laparoscopic colpopexy, sacrospinous ligament suspension was performed as one of multiple corrective surgeries. This patient was subjected to the modified laparoscopic colpopexy and has been observed for over three years. The vaginal vault remains well suspended in this particular case as well as in all remaining patients in Group II. There were neither intraoperative, immediate, nor delayed postoperative complications in all 27 patients, in both groups. Conclusions: (1) When Group I results are compared with Group II results, the new, modified translaparoscopic retroperitoneal-retropubic colpopexy appeared to be a superior technique and very promising, and offers: (a) vaginal cuff suspension by using natural neighbouring genital pelvic structures, (b) reconstruction of pelvic gross/functional anatomy, placement of the vagina adequately in midline position, and alignment of the vagina parallel to the rectum, and re-constitution of proper relationship between the newly suspended vagina and pelvic viscera. (2) It is a safe operation, simple to learn, and easy to execute; however, retroperitoneal-retropubic-mid-pelvis surgical experience as well as advanced operative laparoscopic skill is needed to meet technical demands of the operation.
The Feminist Struggle in the Senegalese Novel: Mariama Ba and Sembene Ousmane

This article analyzes Sembene Ousmane's and Mariama Ba's novels in an attempt to determine whether or not the struggle of Feminism in achieving its inherent objectives is gender based. Indeed, there are those radical feminist critics, especially Euro-Americans, who accuse African male novelists, among other things,of marginalising the Africanwoman. From the narrowed lenses of these critics, the African woman's worst enemy is the African man. On the contrary, this study points out that African female and male novelists pursue the same agenda, the liberation of the Africanwoman from those traditional beliefs that place the African woman at a disadvantaged position.
Multiple x-ray diffraction to determine transverse and longitudinal lattice deformation in shocked lithium fluoride

Experimental and analytic developments are described that utilize multiple x-ray diffraction to determine real-time, lattice deformation in directions parallel and perpendicular to shock-wave propagation in single crystals. Using a monochromatic x-ray source, two Bragg reflections were obtained simultaneously from LiF crystals shocked along the [111] and [100] directions. Symmetry permitted the transverse lattice deformation to be determined by measuring interplanar spacing longitudinally and in one other direction. We chose this to be a [110] direction in both cases because the intensity of the (220) reflection is high and because the transverse deformation component from this measurement is relatively large. Due to the complex geometry involved, an analytic model was required to calculate the (220) peak shift under the deformation conditions of interest. This model was used both to design experiments and to analyze the results. It was determined that shock compression below 4 GPa along the [111] orientation---which results in macroscopic elastic deformation---produced, as expected, no transverse lattice deformation. In contrast, shock compression along the [100] orientation---which results in macroscopic elastic-plastic deformation---produced equal interplanar spacing changes along the longitudinal and transverse directions. The analytic developments and the implications of our results are discussed.
Brain potentials in a memory-scanning task. I. Modality and task effects on potentials to the probes

Event-related potentials were measured in normal young subjects during a memory-scanning paradigm modified from one proposed by Sternberg. The stimuli used were verbal (digits) and non-verbal (musical notes) with the verbal stimuli and notes presented acoustically and the verbal stimuli also presented visually. In this paradigm each set of stimuli was presented for memorization, and then, after a 2 sec interval, a probe item appeared and was identified by the subject as belonging or not belonging to the memorized set. Memorized set sizes of 1, 3 and 5 items were studied. The potentials are described in terms of scalp distribution, latency and amplitude, and are compared with behavioral descriptors of performance (accuracy and reaction time). These potentials are also compared with those evoked by an auditory target-detection task ('odd-ball' paradigm) in the same subject at the same session. The potentials evoked by the probe stimuli consisted of a positive (P50-90), negative (N100-150), positive (P185-225) sequence in the first 250 msec, followed by a later, long-lasting (approximately 700 msec) positive component (labeled P3). This positivity consisted of an earlier component (latency of approximately 350-400 msec) with a frontal distribution, followed by a larger and later parietal component. The amplitude of the frontal component and the latency of the parietal component varied with the number of items in the memorized set differently from behavioral reaction times. Stimulus modality also affected both the amplitude and latency of the sustained parietal positive potential. Memory processes associated with the P3 complex in the 'odd-ball' task and the long-lasting positivity in the memory-scanning task are discussed.
VISUAL ADAPTATION AND CHEMISTRY OF THE RODS

1. The reality of a chemical cycle proposed to describe the rhodopsin system is tested with dark adaptation measurements. 2. The first few minutes of rod dark adaptation are rapid following short, slower following long irradiation. As dark adaptation proceeds, the slow process grows more prominent, and occupies completely the final stages of adaptation. 3. Light adaptation displays similar duality. As the exposure to light of constant intensity lengthens, the visual threshold rises, and independently the speed of dark adaptation decreases. 4. These results conform with predictions from the chemical equations.
A new model for ordinal pain data from a pharmaceutical study

For the pain data analysed previously by Cox and Chuang. This paper proposes a new model that assumes monotone scores for ordered response categories. This proposed model possesses several attractive features and allows a stochastic ordering of the drugs under comparison. Such a model also provides insight regarding the ordinal scale used to classify response. Estimation of the parameters in the model is obtained by use of BMDP3R.
Analytic derivation of optimal imaging conditions for incoherent imaging in aberration-corrected electron microscopes.

Abstract The optimal lens parameters for incoherent imaging using third and fifth-order aberration-corrected electron microscopes are derived analytically. We propose simple models for the point spread function (PSF) and transfer function that give analytic formulae for the lateral resolution and depth resolution. We also derive an analytic formula for the contrast transfer function (CTF) in three dimensions and show that depth sectioning has an information limit equivalent to tomography with a missing cone of 90 ∘ minus the aperture angle.
Benes and Lange respond: reconciling theory and practice in cell counting

Optical disector proponents are understandably enthusiastic about their techniques. Notwithstanding the fact that several critiques of our article have been voiced by central figures in the optical disector movement, every neuroscientist should be permitted to make a judgment as to what form of technology will best accomplish his or her own research goals. Dogma has no place in empirical science.
Polymer-Induced Heteronucleation for Protein Single Crystal Growth: Structural Elucidation of Bovine Liver Catalase and Concanavalin A Forms

Obtaining single crystals for X-ray diffraction remains a major bottleneck in structural biology; when existing crystal growth methods fail to yield suitable crystals, often the target rather than the crystallization approach is reconsidered. Here we demonstrate that polymer-induced heteronucleation, a powerful technique that has been used for small molecule crystallization form discovery, can be applied to protein crystallization by optimizing the heteronucleant composition and crystallization formats for crystallizing a wide range of protein targets. Applying these advances to two benchmark proteins resulted in dramatically increased crystal size, enabling structure determination, for a half century old form of bovine liver catalase (BLC) that had previously only been characterized by electron microscopy, and the discovery of two new forms of concanavalin A (conA) from the Jack bean and accompanying structural elucidation of one of these forms.
A Technique for Estimating the Accuracy of Fish Locations Identified by Radiotelemetry

ABSTRACT Radiotelemetry is a useful tool to describe habitat use by fish, but studies may inaccurately describe microhabitat use due to failure to account for errors when identifying fish locations. We developed a technique that identifies the extent of location errors of a hand-held radiotelemetry system. The ranges of location errors were determined among different observers, between land and water, and at an array of distances (5—125 m) between transmitters and receivers. No significant differences occurred among three observers at distances of 100 m or less or between transmitters on land or in water. Location error increased significantly with distance between transmitter and receiver; mean error was 0.5 m at 5 m and 4.5 m at 100 m. The 95th percentile of location errors was 1.5 m at 5 m and 10.5 m at 100 m. The number of trials needed to define location errors within 20% of the true mean (P ≤ 0.05) was 109 at 5 m and 46 at 100 m. Determination of location error with radiotelemetry equipment can be c...
A statistical measure of theme and structure

This paper describes a computer-assisted analysis of semantic patterning in William Blake'sThe Four Zoas and considers the way in which such patterns contribute to the structure and meaning of the work. The analysis involves examining combinations and recombinations of images across the text for concentrations of images and images groups, recurring images, and patterns in the distribution of individual images and clusters of images. Statistical correlation routines were used to determine the degree of correlation among images across the extire text as well as in specific text segments. Principal components analysis enabled identifying thematic clusters of images, and the distribution of these clusters across these text were in turn examined to determine their patterning. Finally, time series analysis and Fourier analysis were used to find and verify patterns in the distribution of images across the text. Fourier analysis revealed striking patterns in the distribution of imagery in theZoas, which suggests that Blake may have used such patterns to help convey the poem's powerful thematic statements.