bluuebunny/crossref_metadata_2025 huggingface dataset:
The Rhetoric of the Father in Proverbs 1-9
Authors: Pemberton Glenn D.
Published: August 2005

Proverbs 1-9 contains ten instructions/lectures in which a `father' addresses his `son(s)'. These lectures are in many respects similar: they address a `son' or `sons', urge the son(s) to listen, not forget but guard the father's teaching, and affirm the value of this teaching. Despite their similarities, however, rhetorical criticism reveals that the ten lectures may be classified into three groups or subsets on the basis of their rhetoric: (1) calls to attention (1.8-19; 2.1-22; 4.1-9; 4.10-19), (2) calls to remember and obey (3.1-12; 3.21-35; 4.20-27), and (3) warnings against the alien/strange woman (5.1-23; 6.20-35; 7.1-27). Further, although the lectures of each subset possess common features that distinguish them as a group, each lecture also possesses unique features that distinguish it from other group members. One may conclude that Proverbs 1-9 contains three distinct subsets of lectures with diverse members, ten lectures with ten different rhetorical strategies.
Re-presenting Culture and the Self
Authors: McHoul Alec , Rapley Mark
Published: August 2005

We try to show that the fundamental grounds of psychological thinking about the domains of ‘culture’ and ‘the self’ (and their possible connections) are necessarily representationalist in the Cartesian sense. Rehearsing Heidegger’s critique of representationalism as the basic wrong turning taken by modern thinking generally (and by psychology in particular) with respect to what human being is, we move on to the possibility of a counter-representationalist re-specification of the concept of culture. Here we mobilize ideas from Husserl and Heidegger (again), and also from the basic ethnomethodological theory of Sacks and Garfinkel, to argue for the primacy of culture as an order of practical-actional affairs that makes conceptualizations of a putative ‘self’ always an effect of, and subsequent to, that very (cultural) order. Accordingly, we end by briefly analysing an actual case of an explicitly cultural use of a supposedly intensional term, ‘agree’.
Engendering Culture in Psychology
Authors: Burman Erica
Published: August 2005

This paper explores the politics of gender circulating within the discourse of culture in psychology. Two complementary conceptualizations of culture are considered in relation to the politics of gender representation they either afford or disallow. Notions of dominant or mainstream culture typically portray gender as marginal or else as indicative of other markers of difference (whereby the over-visibility of gender reflects its tokenized, reified and homogenized status). Either way, both the centrality and intersectionality of gender and culture are overlooked in ways that bolster the liberal pluralism of multiculturalist discourse. Alternatively, discourses around culture that presume minority status currently function to indicate racialized difference. These not only reify cultural practices in ways that abstract and separate them from the contexts of their emergence and function and so feed into discourses of cultural pathologization, but they also privilege ‘race’ over gender and so, paradoxically, marginalize and even exclude some minority women’s positions, interests and experiences. Within both discourses of culture, the contemporary romanticization and abstraction surrounding notions of ‘community’ is shown to marginalize gender-specific issues posed by the position of minoritization. Drawing on conceptual-political problems posed by prevailing discourses of culture and gender in relation to domestic violence, some examples are offered to indicate how re-conceptualizing the relations between culture, ‘race’ and gender can challenge and change theory, policy and practice.
Rethinking the Study of Miscarriages of Justice:
Authors: Leo Richard A.
Published: August 2005

This article provides a brief history of the study of miscarriages of justice in America. It analyzes the field of wrongful conviction scholarship as three distinct genres: the big-picture studies, the specialized-causes literature, and the true-crime genre. It also analyzes what these literatures have contributed to knowledge about miscarriages as well as their limitations. This article attempts to rethink the study of miscarriages of justice to systematically develop a more sophisticated, insightful, and generalizable criminology of wrongful conviction.
Restorative Justice and Wrongful Capital Convictions
Authors: Brnett Cathleen
Published: August 2005

To date, little attention has been given to the problems associated with restoring or compensating persons who have been wrongfully convicted of serious crimes. Most of the discussion has focused on the legal system as the most appropriate remedy in a retributive justice system, ignoring the unintended consequences of judicial remedies that create barriers to adequately reintegrate individuals into society. This article reviews the strategies currently available to compensate thewrongfullyconvictedanduses therestorative justice framework to proposeanalternative approachthat is extrajudicial, groundedin the executive branch’s responsibilityto provide for the administration of justice.
The Craft of Care: Family Care of Relatives With Advanced Dementia
Authors: de la Cuesta Carmen
Published: August 2005

Family caregiving is attracting more attention from policy makers and service providers, but managing a chronic condition in the home is a very complex activity that usually remains invisible to health care professionals. The study’s purpose was to identify strategies family caregivers used in the home to care for their relatives who have dementia. The author collected data from interviews with 18 caregivers and 2 health care professionals, and from participant observation in caregivers’ support groups and homes. She used constant comparison analysis and describes the Craft of Care, a category that emerged during qualitative analysis. Caregivers craft care by creating ruses in care, a language to communicate, and spaces and devices for caregiving. They sustain the humanity of the patient in the midst of a condition that tends to destroy it.
Institutional Narratives in the Discourse Between Oncology Social Workers and Cancer Patients’ Self-Help Organization
Authors: Kacen Lea , Bakshy Iris
Published: August 2005

In this study, the authors examine a discourse between members of a cancer patients’ self-help organization (CP-SHO) and oncological social workers (OSWs) on support groups for cancer patients. Eight OSWs and 8 CP-SHO volunteers served as the key research population. Using the interpretive-narrative approach to research, the authors apply a variety of data collection methods and a combination of data analysis methods: narrative analysis and discourse analysis. The findings point to the simultaneous existence of two institutional narratives for each organization, one internal and the other external. Discourse between the organizations takes place mainly at the external institutional narrative level, with each body maintaining the mistaken impression that the other’s perception of reality is similar to its own (false consensus). In the meantime, the internal narratives that attest to the latent meaning of the discourse govern the interaction and prevent effective dialogue between the respective organizations.
Speech Impairment in the Postoperative Head and Neck Cancer Patient: Nurses’ and Patients’ Perceptions
Authors: Rodriguez Carmen S. , VanCott Mary Lou
Published: August 2005

Communication between postoperative head and neck cancer patients with speech impairment and their health care providers is challenging. These challenges emerge during a period when the patient must communicate needs related to symptoms such as pain or concerns of significance in the absence of the traditional communication process. Content analysis methods facilitated understanding of the perspective of the postoperative head and neck cancer patient experiencing pain and a speech impairment, and the examination of the nurses’ view in the assessment and management of this population. The authors identified self-report of pain as a critical component of pain assessment regardless of the presence of a speech impairment. Significant levels of frustration were associated with the nurses’ goal of addressing the pain management needs of the speech impaired and the patients’ pursuit of reporting the uniqueness of their pain experience.
What Is Dialogical Research, and Why Should We Do It?
Authors: Frank Arthur W.
Published: August 2005

Social scientists have explored the writing of Russian literary philosopher Bakhtin from a variety of perspectives, but little attempt has been made to apply Bakhtin’s conception of dialogue to the conduct of research and the production of research reports. The author’s questions relate to what dialogical research would look like and the ethical imperative of dialogical research.
The Hunting of the Learning Organization
Authors: Tosey Paul
Published: August 2005

This article addresses the epistemology of learning, as reflected in some discourses of the learning organization. The article is inspired by, and draws substantially from, Lewis Carroll’s ‘Hunting of the Snark’. It employs a broadly systemic theoretical perspective. The article highlights relevant characteristics of Carroll’s fiction and argues for the importance of differentiation between orders of learning, following Bateson’s model of levels of learning. Building on this differentiation of orders of learning, and on the notion of the inevitable paradoxical nature of organizations, the article explores a possible conceptual integration of ‘learning’ and ‘politics’, which Easterby-Smith et al. consider desirable. A question raised is of whether experiences cited as paradigmatic of ‘the learning organization’ are most likely to be transient and emergent. The analysis questions the extent to which such states can be produced through intention and design, and therefore to what extent the wish for these to become permanent states may parallel the hunt for the Snark.
Intuition
Authors: Sinclair Marta , Ashkanasy Neal M.
Published: August 2005

Faced with today’s ill-structured business environment of fast-paced change and rising uncertainty, organizations have been searching for management tools that will perform satisfactorily under such ambiguous conditions. In the arena of managerial decision making, one of the approaches being assessed is the use of intuition. Based on our definition of intuition as a non-sequential information-processing mode, which comprises both cognitive and affective elements and results in direct knowing without any use of conscious reasoning, we develop a testable model of integrated analytical and intuitive decision making and propose ways to measure the use of intuition.
Nursing Students Learn About Complementary and Alternative Health Care Practices
Authors: Groft Jean N. , Kalischuk Ruth Grant
Published: August 2005

Informed by a philosophy that embraces wholeness and balance of body-mind-spirit, the authors each led a 13-week university course in which undergraduate students explored the history and practice of alternative and complementary healing modalities. Students submitted weekly journals chronicling their responses to and understanding of the course material. The journals were examined to gain an understanding of students’ experiences related to all aspects of the course content and process. Thematic analysis revealed a major concept (searching and re-searching) as well as five subconcepts (engaging, opening, hesitating, understanding, and knowing) that represented the iterative process of interacting with and reflecting on the learning of often unfamiliar approaches to healing. Of significant interest was the tremendous personal growth identified by students. Nursing students were also able to recognize the utility of their new awareness and knowledge within the context of nursing care delivery, acknowledging the role of alternative and complementary therapies and treatments in the choices made and care accepted by their clients. Implications of the findings for nursing education include the need to expose students to such information and experiences for improved professional nursing practice and health care in general.
Pediatric Health Care Providers’ Attitudes and Referral Predictors for Therapeutic Massage and Acupuncture
Authors: McLellan Mary C. , Highfield Ellen Silver , Woolf Alan D.
Published: August 2005

The objective of this study was to assess pediatric health providers’ attitudes, experience, and referral patterns with respect to therapeutic massage and acupuncture (TM&A). A written survey of experience with and attitudes about TM&A was distributed to a convenience sample of pediatric health care providers attending a regional postgraduate course in April 2002. Bivariate analyses were performed using Fisher’s exact test and the chisquare statistic. Pediatric care providers’ practices of referring patients to TM&A were associated with their own familiarity with and prior use of TM&A as well as their professed comfort level in discussing these modalities. There were no significant differences by professional status, gender, or years in practice in 42% of the respondents who reported making TM&A referrals. Pediatric health care providers’practices in referring patients for TM&A are positively associated with their familiarity with and personal use of TM&A.
An Auditory Brain-Computer Interface Based on the Self-Regulation of Slow Cortical Potentials
Authors: Pham Mirko , Hinterberger Thilo , Neumann Nicola , Kübler Andrea , Hofmayer Nadine , Grether Anke , Wilhelm Barbara , Vatine Jean-Jacques , Birbaumer Niels
Published: August 2005

Objectives. Communication support for severely paralyzed patients with visual impairment is needed. Therefore, the feasibility of a brain-computer interface (BCI) using auditory stimuli alone, based on the self-regulation of slow cortical potentials (SCPs), was investigated. Methods. Auditory stimuli were used for task and feedback presentation in an SCP self-regulation paradigm. Voluntarily produced SCP responses and measures of communication performance were compared between 3 groups (total of N = 59) of visual, auditory, and cross-modal visual-auditory modality. Electroencephalogram recordings and training from Cz-mastoids were carried out on 3 consecutive sessions. Data of 1500 trials per subject were collected. Results. Best performance was achieved for the visual, followed by the auditory condition. The performance deficit of the auditory condition was partly due to decreased self-produced positivity. Larger SCP response variability also accounted for lower performance of the auditory condition. Cross-modally presented stimuli did not lead to significant learning and control of SCP. Conclusions. Brain-computer communication using auditory stimuli only is possible. Smaller cortical positivity achieved in the auditory condition, as compared to the visual condition, may be a consequence of increased selective attention to simultaneously presented auditory stimuli. To optimize performance, auditory stimuli characteristics may have to be adapted. Other suggestions for enhancement of communication performance with auditory stimuli are discussed.
Coordination of Hemiparetic Locomotion after Stroke Rehabilitation
Authors: Kautz Steven A. , Duncan Pamela W. , Perera Subashan , Neptune Richard R. , Studenski Stephanie A.
Published: August 2005

Objectives. Determine whether a rehabilitation program targeting functional motor recovery of persons with poststroke hemiparesis improved motor coordination. Methods. A subgroup of 20 persons with poststroke hemiparesis (n = 11 in intervention and n =9incontrol group) was investigated from within a larger randomized controlled single-blind clinical trial of 100 patients. Motor coordination was measured using a pedaling task, and subjects in the intervention group pedaled during an intensive broad-based home exercise program that targeted flexibility, strength, balance, and endurance. Coordination variables based on paretic leg pedal forces and EMG of 4 thigh muscles were measured while pedaling pre- and postintervention. Results. Despite extensive pedaling practice, up to 30 half-hour sessions that were progressively more intense, there was no effect (P > 0.05) of the intervention on percent of total work done by the paretic leg, quantitative measures of EMG, or pedaling speed. However, walking speed was improved and pedaling and walking faster were associated after the intervention. Conclusions. There is no evidence of improved locomotor coordination postintervention. The increased walking and pedaling speed was likely achieved by a more proficient use of the same impaired pattern without EMG timing changes, likely because of increased strength and endurance postintervention. A more task-specific intervention may be required to improve coordination, consistent with principles of use-dependent plasticity.
Phosphatidylserine treatment relieves the block to retrovirus infection of cells expressing glycosylated virus receptors
Authors: Coil David A , Miller A Dusty
Published: August 2005

Background

A major determinant of retrovirus host range is the presence or absence of appropriate cell-surface receptors required for virus entry. Often orthologs of functional receptors are present in a wide range of species, but amino acid differences can render these receptors non-functional. In some cases amino acid differences result in additional N-linked glycosylation that blocks virus infection. The latter block to retrovirus infection can be overcome by treatment of cells with compounds such as tunicamycin, which prevent the addition of N-linked oligosaccharides.

Results

We have discovered that treatment of cells with liposomes composed of phosphatidylserine (PS) can also overcome the block to infection mediated by N-linked glycosylation. Importantly, this effect occurs without apparent change in the glycosylation state of the receptors for these viruses. This effect occurs with delayed kinetics compared to previous results showing enhancement of virus infection by PS treatment of cells expressing functional virus receptors.

Conclusion

We have demonstrated that PS treatment can relieve the block to retrovirus infection of cells expressing retroviral receptors that have been rendered non-functional by glycosylation. These findings have important implications for the current model describing inhibition of virus entry by receptor glycosylation.
Neuropsychological measures of attention and memory function in schizophrenia: relationships with symptom dimensions and serum monoamine activity
Authors: Oades Robert D , Röpcke Bernd , Henning Uwe , Klimke Ansgard
Published: August 2005

Background

Some clinical symptoms or cognitive functions have been related to the overall state of monoamine activity in patients with schizophrenia, (e.g. inverse correlation of the dopamine metabolite HVA with delusions or visual-masking performance). However, profiles (as presented here) of the relations of the activity of dopamine, noradrenaline and serotonin to neuropsychologic (dys)functions in major patient sub-groups with their very different symptomatic and cognitive characteristics have not been reported.

Methods

Serum measures of dopamine, noradrenaline and serotonin turnover were examined by regression analyses for the prediction of performance on 10 neuropsychological measures reflecting left- and right-hemispheric and frontal-, parietal- and temporal-lobe function in 108 patients with schizophrenia and 63 matched controls. The neuropsychological battery included tests of verbal fluency, Stroop interference, trail-making, block-design, Mooney faces recognition, picture-completion, immediate and delayed visual and verbal recall. Paranoid and nonparanoid subgroups were based on ratings from the Positive and Negative Syndrome Scale (PANSS). Groups with high and low ratings of ideas-of-reference and thought-disorder were formed from a median split on the Scale for Assessment of Positive Symptoms (SAPS).

Results

Verbal-fluency and Stroop-interference (left frontal and fronto-cingulate function) were negatively associated with noradrenergic turnover in nonparanoid and thought-disordered patients. High dopamine turnover related to speeded trail-making (frontal modulation of set switching) in those with many ideas-of-reference. In contrast, low dopamine turnover predicted poor recall in nonparanoid patients and those with little thought disorder. Serotonin metabolism did not independently contribute to the prediction any measure of cognitive performance. But, with regard to the relative activity between monoaminergic systems, increased HVA/5-HIAA ratios predicted visual-reproduction and Mooney's face-recognition performance (right-hemisphere functions) in highly symptomatic patients. Decreased HVA/MHPG predicted non-verbal recall.

Conclusion

Clinical state and function are differentially sensitive to overall levels of monoamine activity. In particular, right-lateralised cerebral function was sensitive to the relative activities of the monoamines. Increased noradrenergic activity was associated with enhanced frontal but impaired temporal lobe function in nonparanoid syndromes. Low dopaminergic activity predicted poor attentional set control in those with ideas-of-reference, but poor recall in nonparanoid patients. These data, especially the HVA/5-HIAA ratios, provide a basis for planning the nature of antipsychotic treatment aimed at patient specific symptom dimensions and cognitive abilities.
Subluxation: dogma or science?
Authors: Keating Joseph C , Charlton Keith H , Grod Jaroslaw P , Perle Stephen M , Sikorski David , Winterstein James F
Published: August 2005

Subluxation syndrome is a legitimate, potentially testable, theoretical construct for which there is little experimental evidence. Acceptable as hypothesis, the widespread assertion of the clinical meaningfulness of this notion brings ridicule from the scientific and health care communities and confusion within the chiropractic profession. We believe that an evidence-orientation among chiropractors requires that we distinguish between subluxation dogma vs. subluxation as the potential focus of clinical research. We lament efforts to generate unity within the profession through consensus statements concerning subluxation dogma, and believe that cultural authority will continue to elude us so long as we assert dogma as though it were validated clinical theory.
Evolution of the Heart from Bacteria to Man
Authors: BISHOPRIC NANETTE H.
Published: August 2005

Abstract: This review provides an overview of the evolutionary path to the mammalian heart from the beginnings of life (about four billion years ago) to the present. Essential tools for cellular homeostasis and for extracting and burning energy are still in use and essentially unchanged since the appearance of the eukaryotes. The primitive coelom, characteristic of early multicellular organisms (∼800 million years ago), is lined by endoderm and is a passive receptacle for gas exchange, feeding, and sexual reproduction. The cells around this structure express genes homologous to NKX2.5/tinman, and gradual specialization of this “gastroderm” results in the appearance of mesoderm in the phylum Bilateria, which will produce the first primitive cardiac myocytes. Investment of the coelom by these mesodermal cells forms a “gastrovascular” structure. Further evolution of this structure in the bilaterian branches Ecdysoa (Drosophila) and Deuterostoma (amphioxus) culminate in a peristaltic tubular heart, without valves, without blood vessels or blood, but featuring a single layer of contracting mesoderm. The appearance of Chordata and subsequently the vertebrates is accompanied by a rapid structural diversification of this primitive linear heart: looping, unidirectional circulation, an enclosed vasculature, and the conduction system. A later innovation is the parallel circulation to the lungs, followed by the appearance of septa and the four‐chambered heart in reptiles, birds, and mammals. With differentiation of the cardiac chambers, regional specialization of the proteins in the cardiac myocyte can be detected in the teleost fish and amphibians. In mammals, growth constraints are placed on the heart, presumably to accommodate the constraints of the body plan and the thoracic cavity, and adult cardiac myocytes lose the ability to re‐enter the cell cycle on demand. Mammalian cardiac myocyte innervation betrays the ancient link between the heart, the gut, and reproduction: the vagus nerve controlling heart rate emanates from centers in the central nervous system regulating feeding and affective behavior.
Multiple Stem Cell Populations Contribute to the Formation of the Myocardium
Authors: EISENBERG LEONARD M. , MORENO RICARDO , MARKWALD ROGER R.
Published: August 2005

Abstract: Owing to the very rapid growth of the vertebrate embryo following fertilization, an efficient circulatory system needs to be established during the initial stages of development. For that reason, the first functional organ that develops in both the bird and mammalian embryo is the heart. Until recently, the narrative of cardiac development was portrayed in a straightforward manner, with all the myocardium in the mature heart being generated from the expansion of an original pool of myocardial cells present in the early gastrula. It is now known that the story of the developing myocardium is more dynamic, as it is comprises cellular components of multiple ancestries. The de novo addition of myocytes to the developing heart occurs at various points during embryogenesis, as cardiac muscle takes on new members by the absorption of cells that either reside in neighboring nonmuscle tissue or come into contact with the myocardium by entering the heart upon migration or via the circulation. This article reviews what is presently known about cellular populations that contribute to the myocardium and examine reasons why the embryo utilizes multiple cellular sources for forming the cardiac muscle.
Modification of Cellular Communication by Gene Transfer
Authors: DONAHUE J. KEVIN , BAUER A.EXANDER , KIKUCHI KAN , SASANO TETSUO
Published: August 2005

Abstract: Hope has been expressed that gene and cell therapies will one day reduce the morbidity and mortality associated with cardiovascular diseases. Work in these fields has shown that the road from bench to bedside is filled with obstacles. Still, the possibility for treatment or even cure of cardiac disease is real. Continuing work will improve understanding of the underlying physiology and vector biology. The current review focuses on the potential use of gene therapy to affect cellular communication. Included is a review of communication effects on a transcellular level with angiogenesis, AV nodal conduction and sinus nodal automaticity, and effects on an intracellular level with cardiac myocyte repolarization. Challenges facing the field of gene therapy are also reviewed. If these problems can be solved, gene therapy will become a viable alternative for clinical use.
Nitric Oxide and the Heart: Update on New Paradigms
Authors: BELGE C. , MASSION PAUL B. , PELAT M. , BALLIGAND J. L.
Published: August 2005

Abstract: The role of nitric oxide (NO) as a regulator of cardiac contraction was suggested in the early nineties, but a consensual view of its main functions in cardiac physiology has only recently emerged with the help of experiments using genetic deletion or overexpression of the three nitric oxide synthase (NOS) isoforms in cardiomyocytes. Contrary to the effects of exogenous, pharmacologic NO donors, signaling by endogenous NO is restricted to intracellular effectors co‐localized with NOS in specific subcellular compartments. This both ensures coordinate signaling by the three NOS isoforms on different aspects of the cardiomyocyte function and helps to reconcile previous apparently contradictory observations based on the use of non‐isoform‐specific NOS inhibitors. This review will emphasize the role of NOS on excitation‐contraction coupling in the normal and diseased heart. Endothelial NOS and neuronal NOS contribute to maintain an adequate balance between adrenergic and vagal input to the myocardium and participate in the early and late phases of the Frank‐Starling adaptation of the heart. At the early phases of cardiac diseases, inducible NOS reinforces these effects, which may become maladaptive as disease progresses.
The Sarcomeric Control of Energy Conversion
Authors: LEVY CARMIT , TER KEURS HENK E.D.J. , YANIV YAEL , LANDESBERG AMIR
Published: August 2005

Abstract: The Frank‐Starling Law, Fenn Effect, and Suga's suggestions of cardiac muscle constant contractile efficiency establish the dependence of cardiac mechanics and energetics on the loading conditions. Consistent with these observations, this review suggests that the sarcomere control of contraction consists of two dominant feedbacks: (1) a cooperativity mechanism (positive feedback), whereby the number of force‐generating cross‐bridges (XBs) determines the affinity of calcium binding to the troponin regulatory protein; and (2) a mechanical (negative) feedback, whereby the filament shortening velocity affects the rate of XB turnover from the force to the non‐force generating conformation. The study explains the roles of these feedbacks in providing the adaptive control of energy consumption by the loading conditions and validates the dependence of the cooperativity mechanism on the number of strong XBs. The cooperativity mechanism regulates XB recruitment. It explains the cardiac force‐length calcium relationship, the related Frank‐Starling Law of the heart, and the adaptive control of new XB recruitment and the associated adenosine triphosphate (ATP) consumption. The mechanical feedback explains the force‐velocity relationship and the constant and high‐contractile efficiency. These mechanisms were validated by testing the force responses to large amplitude (100 nm/sarcomere) sarcomere length (SL) oscillations, in intact tetanized trabeculae (utilizing 30 μM cyclopiazonic). The force responses to large‐length oscillations lag behind the imposed oscillations at low extracellular calcium concentration ([Ca2+]0) and slow frequencies (<4 Hz, 25°C), yielding counterclockwise hystereses in the force‐length plane. The force was higher during shortening than during lengthening. The area within these hystereses corresponds to the external work generated from new XB recruitment during each oscillation, and it is determined by the delay in the force response. Characterization of the delayed response and its dependence on the SL, force, and calcium allows identification of the regulation of XB recruitment. The direct dependence of the phase on force indicates that XB recruitment is determined directly by the force (i.e., the number of strong XBs) and indirectly by SL or calcium. The suggested feedbacks determine cardiac energetics: 1) the constant and high contractile efficiency is an intrinsic property of the single XB, due to the mechanical feedback; and 2) the XBs are the myocyte sensors that modulate XB recruitment in response to length and load changes through the cooperativity mechanism.
Mitochondria and Ischemia/Reperfusion Injury
Authors: HONDA HENRY M. , KORGE PAAVO , WEISS JAMES N.
Published: August 2005

Abstract: Cardiac ischemia/reperfusion injury results in a variable mixture of apoptotic, necrotic, and normal tissue that depends on both the duration and severity of ischemia. Injury can be abrogated by activation of protective pathways via ischemic and pharmacologic preconditioning. Mitochondria serve as final arbiters of life and death of the cell as these organelles not only are required to generate ATP but also can trigger apoptosis or necrosis. A key mechanism of mitochondrial injury is by the mitochondrial permeability transition (MPT) that has been shown to occur at reperfusion. The article hypothesizes that ischemia/reperfusion promotes MPT in two phases: (1) MPT priming during ischemia occurs as progressive inner mitochondrial membrane leak is accompanied by depressed electron transport in the setting of fatty acid accumulation and loss of cytochrome c and antioxidants; and (2) Triggering of MPT at reperfusion is determined by the interplay of mitochondrial membrane potential (ΔΨm) with mitochondrial matrix Ca, reactive oxygen species, and pH. It has been found that strategies that promote mitochondrial recovery such as pharmacologic preconditioning by diazoxide are mediated by K+‐dependent regulation of matrix volume and ΔΨm, resulting in improved efficiency of ATP synthesis as well as prevention of cytochrome c loss. If mitochondria fail to recover, then MPT and hypercontracture can result as ΔΨm depolarization waves regeneratively cross the cell (0.1 to 0.2 μm/s).
Spatial Regulation of Intracellular pH in the Ventricular Myocyte
Authors: SWIETACH PAWEL , VAUGHAN‐JONES RICHARD D.
Published: August 2005

Abstract: In the cardiac myocyte, an adequate intracellular proton mobility is necessary for coupling sarcolemmal proton transport to bulk cytoplasm during intracellular pH regulation. It is also important for dissipating intracellular pH nonuniformity in response to local acid/base disturbances. Because cardiac myocytes have a high buffering capacity, intracellular H+ mobility is low. Spatial

movements occur via a mobile buffer shuttle that most likely involves intracellular dipeptides. In the present work with isolated ventricular myocytes, it is demonstrated that stimulating a large acid efflux on sarcolemmal Na+‐H+ exchange, results in spatial pHi gradients of up to 0.1 U. These may have important implications for pH‐sensitive processes within the cell, such as contraction. By using computational modeling, it is shown that the gradients can be attributed to the low

mobility. Computational modeling is also used to assess the importance of

mobility in mediating local recovery of pH following an acidosis in a small region of the cell. Results indicate that local mechanisms for

movement will be important in determining the global regulation of intracellular pH.
Electrotonic Cell‐Cell Interactions in Cardiac Tissue: Effects on Action Potential Propagation and Repolarization
Authors: RUDY YORAM
Published: August 2005

Abstract: This article characterizes through computer simulations, the role of cell‐cell interactions and of tissue structure in determining properties of action potential propagation and repolarization in cardiac tissue. The results demonstrate strong interactions between membrane excitatory processes and electrical loading by the passive tissue structure. These interactions modulate the ionic mechanism of conduction and influence conduction velocity and robustness. Cell‐cell interactions also have a strong effect on the dispersion of repolarization in cardiac tissue.
Modulating the strength of cadherin adhesion: evidence for a novel adhesion complex
Authors: Kim Young J. , Sauer Christa , Testa Karla , Wahl James K. , Svoboda Robert A. , Johnson Keith R. , Wheelock Margaret J. , Knudsen Karen A.
Published: August 2005

Adherens junctions and desmosomes are critical for embryogenesis and the integrity of adult tissues. To form these junctions, classical cadherins interact via α- and β-catenin with the actin cytoskeleton, whereas desmosomal cadherins interact with the intermediate filament system. Here, we used a hormone-activated mutant N-cadherin expressed in fibroblasts to show the existence of a novel classical cadherin adhesion system. N-cadherin was fused at its C-terminus to a modified estrogen receptor ligand-binding domain (NcadER) that binds 4-hydroxytamoxifen (4OHT) and expressed in L cells, which lack an endogenous cadherin. Cells with the mutant cadherin (LNER cells) aggregated in the absence of 4OHT, but only in its presence formed tightly compacted aggregates like those formed by L cells expressing wild-type N-cadherin (LN cells). Compaction of LNER cells treated with 4OHT was accompanied by elevated levels of p120ctn in NcadER immunoprecipitates, compared to immunoprecipitates of non-treated cells, but without changes in α- and β-catenin, or actin. Compaction induced by 4OHT was also accompanied by increased interaction of the NcadER with the cytoskeleton and increased vimentin organization. Vimentin co-immunoprecipitated with the NcadER/catenin complex, suggesting an interaction between cadherin and vimentin. The mechanism by which vimentin interacts with the cadherin appears to involve p120ctn as it co-immunoprecipitates and colocalizes with vimentin in the parent L cells, which lack a cadherin and α- and β-catenins. Disrupting the actin cytoskeleton with cytochalasin B inhibited aggregation, whereas knocking down vimentin with specific siRNAs inhibited compaction. Based on our results we propose that a vimentin-based classical cadherin complex functions together with the actin-based complex to promote strong cell-cell adhesion in fibroblasts.
ER stress and SREBP-1 activation are implicated in β-cell glucolipotoxicity
Authors: Wang Haiyan , Kouri Georgia , Wollheim Claes B.
Published: August 2005

The reduction in insulin secretory capacity and β-cell mass observed in type 2 diabetes is thought to be caused by glucolipotoxicity secondary to hyperglycemia and hyperlipidemia. Our aim in this study was to elucidate the underlying molecular mechanisms. We found a strong correlation between chronic high-glucose treatment and SREBP-1c activation in INS-1 cells and rat islets. Both high-glucose treatment and SREBP-1c activation in INS-1 cells resulted in lipid accumulation, impaired glucose-stimulated insulin secretion, apoptosis, and strikingly similar gene expression patterns, including upregulation of lipogenic and pro-apoptotic genes and downregulation of IRS2, Bclxl and Pdx1. These lipotoxic effects of high glucose were largely prevented by induction of a dominant-negative mutant of SREBP-1c, suggesting SREBP-1c is a major factor responsible for β cell glucolipotoxicity. Moreover, overexpression of another lipogenic transcription factor, ChREBP, in INS-1 cells did not cause lipotoxicity. Intriguingly, chronic high glucose treatment in INS-1 cells led to pronounced induction of the ER stress marker genes, BIP and Chop10. Treatment of rat islets with both chronic high glucose and two ER stress inducers, thapsigargin and tunicamycin, enhanced SREBP-1 binding to the human IRS2 promoter. These results suggest that SREBP-1 activation caused by ER stress is implicated in β-cell glucolipotoxicity.
Direct Quantitative Analysis from Thin-Layer Chromatography Plates Using Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry
Authors: Nicola Anthony J. , Gusev Arkady I. , Hercules David M.
Published: August 2005

Direct quantitative analysis using thin-layer chromatography (TLC) coupled with matrix-assisted laser desorption/ionization mass spectrometry (MALDI) has been demonstrated. An internal standard and a data collection protocol were used for analysis directly from TLC plates to compensate for shot-to-shot signal degradation, as well as deviations of analyte and internal standard spatial distributions within the TLC spot. Cocaine hydrochloride was used as a model compound for this study, and cocaine- d3 was used as the internal standard. Quantitative analysis by TLC/MALDI yielded comparable results to those obtained with stainless steel substrates (the standard MALDI method) for point-to-point repeatability, % RSD of the standard curve, and measurement precision. For silica gel and reverse-phase TLC plates, the relative standard deviation of the standard curve slope was better than 3%, the relative standard deviations of the analyte/internal standard intensity ratios ranged from 3.8% to 9.5%, the precision was estimated to be better than 12%, and the detection limits were estimated to be 60 pg for both TLC plate types. Quantitative analysis using stainless steel substrates yielded a lower detection limit than that obtained by TLC/MALDI by a factor of six. Perspectives for improving the detection limits of direct TLC/MALDI quantitative analysis are discussed. Index Headings: MALDI; TLC; Quantification.
Reaction Monitoring in Explorative Organic Synthesis Using Fiber-Optical NIR Spectroscopy and Principal Component Analysis
Authors: Bjørsvik Hans-René
Published: August 2005

A method of combining spectroscopy and multivariate data analysis for obtaining quantitative information on how a reaction proceeds is presented. The method is an approach for the explorative synthetic organic laboratory rather than the analytical chemistry laboratory. The method implements near-infrared spectroscopy with an optical fiber transreflectance probe as instrumentation. The data analysis consists of decomposition of the spectral data, which are recorded during the course of a reaction by using principal component analysis to obtain latent variables, scores, and loading. From the scores and the corresponding reaction time, it is possible to obtain a reaction profile. This reaction profile can easily be recalculated to obtain the concentration profile over time. This calculation is based on only two quantitative measurements, which can be (1) measurement from the work-up of the reaction or (2) chromatographic analysis from two withdrawn samples during the reaction. The method is applied to the synthesis of 3-amino-propan-1,2-diol.
Effect of Chlorinated Hydrocarbons on the Fluorescence Emission Spectra of 1,3-Bis-(1-Pyrene)Propane in Solutions and Poly(Vinyl Alcohol) Films
Authors: Krech John H. , Rose-Pehrsson Susan L.
Published: August 2005

This paper reports on our investigation of 1,3-bis-(1-pyrene)propane (bpp) as a potential probe for chlorinated hydrocarbons. Changes in the emission spectra of bpp in methanol solutions, upon addition of methylene chloride, chloroform, or carbon tetrachloride, are described. Dramatic changes in the emission spectrum were noted for CCl4, compared to the other additives. These effects are explained by the preferential solvation of bpp by CCl4 and the formation of an excited-state complex (exciplex), leading to quenching of the excimer emission and, ultimately, the monomer emission. When solutions of bpp in the neat chlorinated hydrocarbons were exposed over time to 350-nm light, changes in the emission spectrum were noted for all solvents. Changes in both the excitation and emission spectra of bpp in CCl4 are related to exciplex formation, leading to irreversible formation of photochemical products. Poly(vinyl alcohol) films containing bpp were exposed to CH2C12, CHC13, or CCl4 vapors, and trends consistent with the solution study were observed. A rapid decrease in bpp excimer emission, upon exposure to CCl4 vapors, was observed. The effects of CCl4 in air and argon atmospheres on the bpp/PVA films were also investigated, with oxygen quenching limiting the ability of this system to detect low concentrations of CCl4.
Liquid Filters for UV Resonance Raman Spectroscopy
Authors: Kleimeyer James A. , Fister Julius C. , Zimmerman John , Harris Joel M.
Published: August 2005

Solutions of organic compounds are proposed as viable high-pass, Rayleigh rejection filters for ultraviolet resonance Raman spectroscopy. The steep transmittance curves of these solutions effectively reject elastically scattered light in this region while passing Raman-shifted frequencies. The materials used in the filters are readily available and inexpensive, and the solutions are easily prepared. Filters for four lines in the range of 288 nm to 342 nm from a Raman-shifted 3rd and 4th harmonic of a Nd:YAG laser are presented, although the principle of preparing similar liquid filters can be applied to virtually any near-UV wavelength. The use of these filter solutions in conjunction with a single monochromator was found to significantly reduce levels of elastically scattered light without sacrifice of optical throughput; Raman scattering at frequency shifts within 200 cm−1 of the Rayleigh line could be observed, and the transmittance at shifts >1000 cm−1 was ≥80%. The Rayleighline rejection efficiencies for the filters in this study are modest (102–103) compared with those for filters employed in the visible region; but they can be easily boosted by increasing the chromophore concentration or filter pathlength with a trade-off of throughput for Raman scattering at small wavenumber shifts.
Modeling Particle Size and Clumping Effects in the IR Absorbance Spectra of Dilute Powders
Authors: Pecharromán Carlos , Iglesias Juan E.
Published: August 2005

The calculation of the IR absorbance of a powdered crystalline, ionic material, diluted in an appropriate IR-transparent matrix in a known proportion, is in principle possible, provided that the size and shape distributions of the particles, as well as the optical parameters of the bulk material, and those of the matrix, are known, and, in the case of the FT-IR technique, whether absolute calibration is possible, particularly at high absorbance values. In practice, a close match between observed and calculated absorbance is hindered by several factors intrinsic to the sample that are difficult to quantify, such as the degree of crystallinity of the particles and the very common clumping and aggregation of these particles, which produce a serious problem in the determination of the real filling factor of the composite sample. Some remedies to these problems are proposed in this paper and are applied to several well-known materials.
Detection of Flow Injection Analysis by Acousto-Optic Tunable Filter-Based Fluorimetry and its Application in the Determination of Solvent Polarity
Authors: Tran Chieu D. , Lu Jian
Published: August 2005

The instrumentation development of a fluorescence detector for flow injection analysis (FIA) based on an acousto-optic tunable filter (AOTF) is reported. The unique features of the AOTF—namely, its all-solid-state, compact, fast-scanning, and high-resolution characteristics—make it possible to develop the first fluorescence detector for FIA which is capable of recording the whole fluorescence spectrum with fine vibronic structure of the compound as it is flowing through the FIA detector. This capability, in turn, makes it possible to use this detector for the determination of the polarity of any sample by doping it with a small amount of pyrene and measuring the ratio of fluorescence intensities of band 1 and band 3. Because the sample in this case is flowing through the FIA instrument, it can be a mixture of two different solvents or surfactants by operating the FIA instrument under gradient condition. Polarity of any mixtures of solvents and surfactants can be simply, rapidly, and economically (in terms of the amount of samples and the time needed for measurements) determined.
Qualitative Analysis of Oil Sand Slurries Using On-Line NIR Spectroscopy
Authors: Friesen Waldemar I.
Published: August 2005

The development of a reliable on-line method to monitor process streams is important for improved process control in oil sand extraction plants. The suitability of diffuse reflectance near-infrared (NIR) spectroscopy for this purpose has been tested in a pilot plant environment. Spectra of a feed slurry flowing through a pipe were measured with the use of an on-line fiber-optic probe. Data were collected throughout a nine-hour period during which ore type and slurry water content were varied. The feasibility of monitoring feed stream conditions is demonstrated by principal component analysis of the measured spectra. Clustering of these spectra according to ore type and water content enables the detection of deviations from and transitions between steady-state conditions of the process. Estimates are given of characteristic times for the process to reach a steady state after a change in condition has been initiated. The use of artificial neural networks for classifying spectra on the basis of ore type is also illustrated.