bluuebunny/crossref_metadata_2025 huggingface dataset:
Anemia, transfusions and hospital outcomes among critically ill patients on prolonged acute mechanical ventilation: a retrospective cohort study
Authors: Zilberberg Marya D , Stern Lee S , Wiederkehr Daniel P , Doyle John J , Shorr Andrew F
Published: April 2008

Introduction

Patients requiring prolonged acute mechanical ventilation (PAMV) represent one-third of those who need mechanical ventilation, but they utilize two-thirds of hospital resources devoted to mechanical ventilation. Measures are needed to optimize the efficiency of care in this population. Both duration of intensive care unit stay and mechanical ventilation are associated with anemia and increased rates of packed red blood cell (pRBC) transfusion. We hypothesized that transfusions among patients receiving PAMV are common and associated with worsened clinical and economic outcomes.

Methods

A retrospective analysis of a large integrated claims database covering a 5-year period (January 2000 to December 2005) was conducted in adult patients receiving PAMV (mechanical ventilation for ≥ 96 hours). The incidence of pRBC transfusions was examined as the main exposure variable, and hospital mortality served as the primary outome, with hospital length of stay and costs being secondary outcomes.

Results

The study cohort included 4,344 hospitalized patients receiving PAMV (55% male, mean age 61.5 ± 16.4 years). Although hemoglobin level upon admission was above 10 g/dl in 75% of patients, 67% (n = 2,912) received at least one transfusion, with a mean of 9.1 ± 12.0 units of pRBCs transfused per patient over the course of hospitalization. In regression models adjusting for confounders, exposure to pRBCs was associated with a 21% increase in the risk for hospital death (95% confidence interval [CI] = 1.00 to 1.48), and marginal increases in length of stay (6.3 days, 95% CI = 5.1 to 7.6) and cost ($48,972, 95% CI = $45,581 to $52,478).

Conclusion

Patients receiving PAMV are at high likelihood of being transfused with multiple units of blood at relatively high hemoglobin levels. Transfusions independently contribute to increased risk for hospital death, length of stay, and costs. Reducing exposure of PAMV patients to blood may represent an attractive target for efforts to improve quality and efficiency of health care delivery in this population.
Calpain-mediated regulation of the distinct signaling pathways and cell migration in human neutrophils
Authors: Katsube Masataka , Kato Takayuki , Kitagawa Maki , Noma Haruyoshi , Fujita Hisakazu , Kitagawa Seiichi
Published: April 2008

We studied the mechanisms underlying calpain inhibition-mediated human neutrophil migration. MAPKs, including ERK, p38, and JNK, MEK1/2, MAPK kinase 3/6 (MKK3/6), PI-3K/Akt, c-Raf, and p21-activated kinase (PAK; an effector molecule of Rac) were rapidly (within 30 s) activated in neutrophils upon exposure to calpain inhibitors (PD150606 and N-acetyl-Leu-Leu-Nle-CHO) but not PD145305 (inactive analog of PD150606). Following activation of these pathways, neutrophils displayed active migration (chemotaxis), which was sustained for more than 45 min. The studies with pharmacological inhibitors suggest that calpain inhibition-mediated neutrophil migration is mediated by activation of MEK/ERK, p38, JNK, PI-3K/Akt, and Rac. NSC23766 (Rac inhibitor) and pertussis toxin (PTX) suppressed calpain inhibitor-induced phosphorylation of distinct signaling molecules (PAK, c-Raf, MEK1/2, ERK, MKK3/6, p38, JNK, and Akt) as well as cell migration, suggesting that the PTX-sensitive G protein and Rac axis may be a possible key target of calpain inhibitors. Differentiated neutrophil-like HL-60 cells but not undifferentiated cells displayed cell migration and activation of MAPKs and PI-3K/Akt on calpain inhibition. These findings suggest that constitutively active calpain negatively regulates activation of the distinct signaling pathways and cell migration in resting neutrophils, and this regulatory system develops during differentiation into mature neutrophils.
Nomogram for the Prediction of Having Four or More Involved Nodes for Sentinel Lymph Node–Positive Breast Cancer
Authors: Katz Angela , Smith Barbara L. , Golshan Mehra , Niemierko Andrzej , Kobayashi Wendy , Raad Rita Abi , Kelada Alexandra , Rizk Levi , Wong Julia S. , Bellon Jennifer R. , Gadd Michele , Specht Michelle , Taghian Alphonse G.
Published: April 2008

Purpose

The standard of care for patients with a positive (+) sentinel lymph node (SLN) is axillary dissection; however, for various reasons, some SLN+ patients do not undergo dissection. The purpose of this study was to define possible predictors of having four or more involved nodes to provide information for clinicians and patients making decisions about adjuvant chemotherapy and radiation.

Patients and Methods

We reviewed the records of 402 patients with invasive breast cancer and one to three involved SLNs who underwent completion axillary dissection at two academic cancer centers. None of these patients received neoadjuvant chemotherapy. Factors associated with having four or more involved axillary nodes (SLNs and non-SLNs) were evaluated by univariate and multivariate logistic regression analysis.

Results

Eighty-seven patients had four or more positive nodes. On multivariate analysis, having four or more SLNs was associated with tumor histology, primary tumor size, lymphovascular space invasion, extranodal extension, the number of involved SLNs, the number of uninvolved SLNs, and the size of the largest SLN metastasis. A nomogram to predict the probability of having four or more nodes based on patients’ pathologic data was developed from the multivariate logistic regression model. A separate previously published data set of 206 SLN+ patients treated at a community hospital in another city was used to validate this model.

Conclusion

Patients with a low probability of having four or more nodes can be identified from known pathologic features. The nomogram developed will be helpful to clinicians making adjuvant treatment recommendations.
Serum TIMP-1 and Response to the Aromatase Inhibitor Letrozole Versus Tamoxifen in Metastatic Breast Cancer
Authors: Lipton Allan , Leitzel Kim , Chaudri-Ross Hilary A. , Evans Dean B. , Ali Suhail M. , Demers Laurence , Hamer Peter , Brown-Shimer Sheryl , Pierce Karen , Gaur Victor , Carney Walter
Published: April 2008

Purpose

To determine the effect of elevated serum TIMP-1 on the response of patients with metastatic breast cancer to an aromatase inhibitor versus tamoxifen.

Patients and Methods

Five hundred twenty-two patients estrogen receptor–positive metastatic breast cancer were randomly assigned to receive first-line hormone therapy with letrozole or tamoxifen. Serum tissue inhibitor of metalloproteinases-1 (TIMP-1) levels were measured using an enzyme-linked immunosorbent assay.

Results

Pretreatment serum TIMP-1 was elevated in 120 (23%) of 522 patients. Patients with elevated serum TIMP-1 had a significantly reduced objective response rate (19.2% v 30.6%; odds ratio, 0.54; P = .01), duration of response (median, 15.5 v 26.2 months; P = .001), time to treatment progression (TTP; median, 4.5 v 9.2 months; HR, 1.78; P = .0001), time to treatment failure (median, 3.5 v 9.0 months; HR, 1.77; P = .0001), and overall survival (median, 20.3 v 35.8 months; HR, 1.77; P = .0001) compared with patients with normal pretreatment TIMP-1 levels. Letrozole was superior to tamoxifen in both the normal serum TIMP-1 group (median TTP, 11.8 v 8.6 months; P = .003) and in the elevated serum TIMP-1 group (median, 6.1 v 3.2 months; P = .03) In multivariate analysis, elevated serum TIMP-1 remained an independent predictor of both shorter TTP (HR, 1.46; P = .002) and survival (HR, 1.44; P = .002), as did serum HER-2. Combined analysis of both serum TIMP-1 and HER-2/neu conferred additional ability to predict significantly different clinical outcomes compared to using either biomarker alone.

Conclusion

Patients with elevated pretreatment serum TIMP-1 had a significantly reduced response and survival. Serum TIMP-1 was an independent predictive and prognostic factor. Blockade of TIMP-1 and HER-2/neu activity may be beneficial in a subset of patients with breast cancer.
Structural and molecular basis for hyperspecificity of RNA aptamer to human immunoglobulin G
Authors: Miyakawa Shin , Nomura Yusuke , Sakamoto Taiichi , Yamaguchi Yoshiki , Kato Koichi , Yamazaki Satoko , Nakamura Yoshikazu
Published: April 2008

Potential applications for functional RNAs are rapidly expanding, not only to address functions based on primary nucleotide sequences, but also by RNA aptamer, which can suppress the activity of any target molecule. Aptamers are short DNA or RNA folded molecules that can be selected in vitro on the basis of their high affinity for a target molecule. Here, we demonstrate the ability of RNA aptamers to recognize—and bind to—human IgG with high specificity and affinity. An optimized 23-nucleotide aptamer, Apt8-2, was prepared, and was shown to bind to the Fc domain of human IgG, but not to other IgG's, with high affinity. Apt8-2 was observed to compete with protein A, but not with the Fcγ receptor, for IgG binding. NMR chemical-shift analyses localized the aptamer-binding sites on the Fc subdomain, which partially overlaps the protein A binding site but not the Fcγ receptor binding site. The tertiary structures of the predicted recognition sites on the Fc domain differ significantly between human IgG and other species of IgGs; this, in part, accounts for the high specificity of the selected aptamer. Apt8-2 can therefore be used as a protein A alternative for affinity purification of human IgG and therapeutic antibodies. Using Apt8-2 would have several potential advantages, raising the possibility of developing new applications based on aptamer design.
RNase P cleaves the adenine riboswitch and stabilizes pbuE mRNA in Bacillus subtilis
Authors: Seif Elias , Altman Sidney
Published: April 2008

RNase P from Bacillus subtilis cleaves in vitro the adenine riboswitch upstream of pbuE, which codes for an adenine efflux pump. The guanine riboswitch, encoded upstream of xpt-pbuX operon, is not cleaved. The cleavage sites do not occur at any predicted structures that should be recognized by RNase P in the theoretical model of the adenine riboswitch. However, it is possible to draw alternative secondary structure models that match the apparent requirements for RNase P substrates at these cleavage sites. Support for these models is provided by appropriate mutagenesis experiments. Adenine showed no effect on the cleavage in vitro of the pbuE adenine riboswitch by RNase P holoenzyme from B. subtilis. The results of genetic experiments performed in B. subtilis support the cleavage of adenine riboswitch by RNase P in vivo and suggest that it induces the stabilization of pbuE mRNA under normal conditions.
Trypanosoma brucei RNA editing protein TbMP42 (band VI) is crucial for the endonucleolytic cleavages but not the subsequent steps of U-deletion and U-insertion
Authors: Law Julie A. , O'Hearn Sean F. , Sollner-Webb Barbara
Published: April 2008

Trypanosome mitochondrial mRNAs achieve their coding sequences through RNA editing. This process, catalyzed by ∼20S protein complexes, involves large numbers of uridylate (U) insertions and deletions within mRNA precursors. Here we analyze the role of the essential TbMP42 protein (band VI/KREPA2) by individually examining each step of the U-deletional and U-insertional editing cycles, using reactions in the approximately linear range. We examined control extracts and RNA interference (RNAi) extracts prepared soon after TbMP42 was depleted (when primary effects should be most evident) and three days later (when precedent shows secondary effects can become prominent). This analysis shows TbMP42 is critical for cleavage of editing substrates by both the U-deletional and U-insertional endonucleases. However, on simple substrates that assess cleavage independent of editing features, TbMP42 is similarly required only for the U-deletional endonuclease, indicating TbMP42 affects the two editing endonucleases differently. Supplementing RNAi extract with recombinant TbMP42 partly restores these cleavage activities. Notably, we find that all the other editing steps (the 3′-U-exonuclease [3′-U-exo] and ligation steps of U-deletion and the terminal-U-transferase [TUTase] and ligation steps of U-insertion) remain at control levels upon RNAi induction, and hence are not dependent on TbMP42. This contrasts with an earlier report that TbMP42 is a 3′-U-exo that may act in U-deletion and additionally is critical for the TUTase and/or ligation steps of U-insertion, observations our data suggest reflect indirect effects of TbMP42 depletion. Thus, trypanosomes require TbMP42 for both endonucleolytic cleavage steps of RNA editing, but not for any of the subsequent steps of the editing cycles.
Disentangling Pioneering Cost Advantages and Disadvantages
Authors: Boulding William , Christen Markus
Published: April 2008

Existing literature discusses a number of possible pioneering cost advantages and disadvantages. In this paper, we empirically test three different sources of long-term pioneering cost advantage—experience curve effects, preemption of input factors, and preemption of ideal market space—and three different sources of pioneering cost disadvantage—imitation, vintage effects, and demand orientation. We disentangle these sources by breaking total cost of a business unit into three different components—purchasing, production, and selling, general, and administrative (SG&A) costs—and identifying conditions that intensify or reduce the effect of the proposed source. Using two samples of business units, one for consumer goods and one for industrial goods, we find support for five of the six sources of pioneering cost advantage and disadvantage in both samples, while the advantage due to preemption of ideal market space is limited to the consumer goods sample. The unconditional analysis shows a pioneering purchasing cost advantage but even larger pioneering production and SG&A cost disadvantages. The complexity of our obtained findings suggests that managers need to think carefully about their particular conditions before making assumptions about the cost and, therefore, profit implications of a pioneering strategy.
Practice Prize Winner—A Nested Logit Model of Product and Transaction-Type Choice for Planning Automakers' Pricing and Promotions
Authors: Silva-Risso Jorge , Ionova Irina
Published: April 2008

We develop a consumer response model to evaluate and plan pricing and promotions in durable-good markets. We discuss its implementation in the U.S. automotive industry, which “spends” about $45 billion each year in price promotions. The approach is based on a random effects multinomial nested logit model of product (e.g., a vehicle model, such as Hyundai Tucson), and transaction-type choice. Transaction types include combinations of acquisition types (e.g., purchase versus lease) and pricing instruments (cash rebates, reduced APR financing, lease payment discounts). We estimate the model using hierarchical Bayes methods to capture response heterogeneity at the local market level. We find key characteristics unique to durable-good markets. First, consumers are heterogeneous in both their brand and transaction-type preferences. Second, consumers differ in their overall price sensitivity as well as in their relative sensitivity to alternative pricing instruments (e.g., cash discounts, reduced monthly payments). Third, the most effective pricing programs tend to be those in which automakers offer consumers a menu of options to choose from (e.g., a choice among a cash discount, reduced interest rate financing, or a lease payment discount). We illustrate the model through an empirical application to a sample of data drawn from J.D. Power transaction records in the entry SUV segment and discuss examples of actual implementations.
Are Overconfident CEOs Born or Made? Evidence of Self-Attribution Bias from Frequent Acquirers
Authors: Billett Matthew T. , Qian Yiming
Published: April 2008

We explore the history of mergers and acquisitions made by individual CEOs. Our study has three main findings: (1) CEOs' first deals exhibit zero announcement effects while their subsequent deals exhibit negative announcement effects; (2) while acquisition likelihood increases in the performance associated with previous acquisitions, previous positive performance does not curb the negative wealth effects associated with subsequent deals; and (3) CEOs' net purchase of stock is greater preceding subsequent deals than it is for first deals. We interpret these results as consistent with self-attribution bias leading to overconfidence. We also find evidence that the market anticipates future deals based on the CEO's acquisition history and impounds such anticipation into stock prices.
Integration Through Incentives Within Differentiated Organizations
Authors: Kretschmer Tobias , Puranam Phanish
Published: April 2008

Drawing on the concepts of organizational differentiation and integration, we present a formal analysis of the manner in which these two consequences of specialization shape the effectiveness of collaborative incentives in complex organizations. We show that ignoring the coordination challenges created by differentiation does not merely impede the achievement of gains from integration through incentives, but can lower organizational performance below the levels achieved when such gains are simply ignored. Thus, treating interunit collaboration purely as a problem of motivating cooperation can be counterproductive. We describe implications in the context of interdivisional relationships and postmerger integration.
Recovered memories of childhood sexual abuse: Current findings and their legal implications
Authors: Geraerts Elke , Raymaekers Linsey , Merckelbach Harald
Published: April 2008

Recent research on recovered memories of childhood sexual abuse has shown that there are at least two types of recovered memory experiences: those that are gradually recovered within the context of suggestive therapy and those that are spontaneously recovered, without extensive prompting or explicit attempts to reconstruct the past. By focusing on well‐known imperfections of human memory, we were able to find differing origins for these recovered memory experiences, with people recovering memories through suggestive therapy being more prone to forming false memories, and with people reporting spontaneously recovered memories being more prone to forgetting prior incidences of remembering. Moreover, the two types of recovered memory reports are associated with differences in corroborative evidence, suggesting that memories recovered spontaneously, outside of suggestive therapy, are more likely to correspond to genuine abuse events. In this paper, we summarize recent research on recovered memories and we argue that these scientific findings should be applied in the justice system, but also in clinical practice.
Expression of Somatostatin and Somatostatin Receptor Subtypes 1–5 in Human Normal and Diseased Kidney
Authors: Bhandari Sunil , Watson Neil , Long Ervine , Sharpe Steve , Zhong Wenwen , Xu Shang-Zhong , Atkin Stephen L.
Published: April 2008

Somatostatin mediates inhibitory functions through five G protein–coupled somatostatin receptors (sst1-5). We used immunohistochemistry, immunofluorescence, and RT-PCR to determine the presence of somatostatin receptors sst1, sst2A, sst2B, sst3, sst4, and sst5 in normal and IgA nephropathy human kidney. All somatostatin receptors were detected in the thin tubules (distal convoluted tubules and loops of Henle) and thick tubules (proximal convoluted tubules) in the tissue sections from nephrectomy and biopsy samples. Immunopositive sst1 and sst4 staining was more condensed in the cytoplasm of tubular epithelial cells. In normal kidney tissue sections, podocytes and mesangial cells in the glomeruli stained for sst1, sst2B, sst4 and sst5, and stained weakly for sst3. In IgA kidney tissue, the expression of somatostatin receptors was significantly increased with particular immmunopositive staining for sst1, sst2B, sst4, and sst5 within glomeruli. In the epithelial cells, the staining for sst2B and sst4 in proximal tubules and sst1, sst2B, and sst5 in distal tubules was increased. The mRNA expression of sst1-5 was also detected by RT-PCR. Somatostatin and all five receptor subtypes were ubiquitously distributed in normal kidney and IgA nephropathy. The increased expression of somatostatin receptors in IgA nephropathy kidney might be the potential pathogenesis of inflammatory renal disease.
Modelling Attentional Effects with Head-up Displays
Authors: McCann Robert S. , Lynch Jeannie , Foyle David C. , Johnston James C.
Published: April 2008

Previous research (McCann, Foyle, & Johnston, 1993) has shown that in a simulated approach to a runway, performance of a choice reaction time task is faster when all relevant information is available on the HUD or in the world, compared to when information has to be acquired from both domains. The present experiment tested two attentional models of these results: attention switching and attention sharing. Removing differential motion cues from the display, so that both the HUD and the world were motionless, attenuated the domain effect. The attenuated difference reflected both slower responses on within-domain trials and faster responses on between-domain trials. We conclude that performance with Head-Up Displays is affected by both attention switching and the degree to which attention is shared between domains.
Comparison of Eight Color and Gray Scales for Displaying Continuous 2D Data
Authors: Merwin David H. , Wickens Christopher D.
Published: April 2008

The use of various dimensions of color to encode continuous data has become commonplace with the advent of sophisticated computing hardware and software. Applications users can choose from a variety of color pallets as well as create their own for viewing digitized data sets. A primary HCI question emerging from this expanded availability of color for data display is how best to map color dimensions to data dimensions for various applications. The current study examined a subset of the perceptual/cognitive processes underlying pattern recognition tasks, whose efficacy could be affected by the nature the color scale used to visualize the data being viewed. Three types of observers' judgments were examined: absolute discrimination of a value; relative judgment of the difference between two values; and a rank order judgment of 4 values. These values were expressed in the color of a specific region in images displayed using eight different color and gray scales. Preference ratings were collected for the color scales. Grey scales were best for rank ordering tasks, while a blue-green-yellow scale proved superior for an absolute independent task. Scale preferences did not necessarily agree with performance. Implications of the findings and future research are discussed.
Effects of Contrast on Perceived Size of Visual Patterns: Theory, Data, and Implications
Authors: Kirkland B. Arthur , Davis Elizabeth Thorpe , Yager Dean , Surdick Troy
Published: April 2008

The perceived spatial frequency of a visual pattern can vary with changes in contrast. Because size is inversely related to spatial frequency and because perceived size is an important distance cue, this has implications for task performance in a variable contrast environment. These environments are common in everyday situations, such as driving in the fog, and in the use of night vision devices. Understanding the underlying visual mechanisms of this effect would help us design systems that compensate for the effect. This understanding also could further develop models of the human low-level visual processes. However, most testing of perceived size and contrast has been done at relatively high contrast levels. This research is conducted at contrast levels near detection threshold. This range allows a more thorough testing of different models of contrast detection. We tested two versions of a multiple spatial-frequency channels model of contrast perception. One model assumes a single set of channels functioning throughout the dynamic range of contrasts used here, the other assumes two sets of channels based on the parvo and magnocellular systems. Our results support the hypothesis that there is a single set of channels at work in the contrast range tested.
Individual Differences in Processing Strategy for a Bargraph Display
Authors: Nowicki Julie R. , Coury Bruce G.
Published: April 2008

The bargraph has been described in several ways: as a separable display, as an integral display, and as a configural display with emergent features. The versatility of the bargraph may be in part due to the support it provides for different individual processing strategies. This research identifies two general types of strategies - holistic and analytic - which are developed by individuals to solve a classification problem on the bargraph. Multidimensional scaling (MDS), response times, and verbal reports are used to analyze individual strategies. Individuals who developed holistic strategies produced significantly faster reaction times, and reported simple, efficient strategies, with the emergent feature of bargraph shape as an important dimension. The results indicate that the bargraph provides perceptual features which can support several general types of processing strategy.
Visual Cues for Vehicle Control
Authors: Kaiser Mary K. , Johnson Walter W. , Andersen George J. , Andre Anthony D. , Banks Martin S. , Flach John M.
Published: April 2008

Since Gibson's pioneering work in the 1950s, there has been increasing interest in describing the dynamic visual cues operators extract from the “out-the-window” scene to utilize in vehicular control. Despite this interest, we are still a long way from an adequate understanding of what optical information is utilized, and how the information is integrated into an active control strategy. There are a number of reasons for this apparent shortfalling. First, it is difficult to isolate a candidate optical cue; geometry dictates that several candidate cues will co-vary in any natural scene (e.g., edge rate and flow rate). The experimental isolation of an optical cue often results in visual scenes which are quite unnatural, creating the possibility that strategies used in the experimental setting will not generalize to operational settings. Also, much of the laboratory work has focused on demonstrating people's sensitivity to optical variables, utilizing passive verbal judgments rather than active control paradigms. Whereas the demonstration of sensitivity to an optical cue is a logically necessary step, such a demonstration is not sufficient to verify its utility in an active control task. Further, there is the need for an adequate description of the task demands, allowing a proper mapping between what the controller is trying to achieve and the information available to accomplish the task; no single cue (or set of cues) will be appropriate for all vehicular control tasks. Finally, given the robust and opportunistic nature of the human perceptual system, it is possible that the visual cues used for vehicle control will vary from individual to individual, or even within an individual depending on which cues are available and salient in the control environment. The participants in this panel are well versed in the challenges of studying visually based vehicular control. Their presentations will reflect the lessons learned in this field, as well as insights regarding how current and future research can better realize the promise of this domain.
Development of a Microcomputer Based Battery of Temporal Factors Tests
Authors: Kennedy R. S. , Ritter A. D. , Berbaum K. S. , Smith M. G.
Published: April 2008

Our industrialized society places a premium on the ability to resolve visually fine-spatial detail in the environment. But the perceptual demands of new display systems may involve temporal acuity as much as spatial acuity. Inability to “switch” attention and fixation rapidly from one visual display to another may be a major factor in the “human error” component. We hypothesize that individuals differ in their temporal visual acuity and, if so, then scores on tests which tap this capability would be predictive of productivity on jobs and activities with these demand characteristics. A battery of five temporal factors tests implemented on a portable lap-top microcomputer was administered over several trials to 44 subjects. The tests exhibited satisfactory metric properties (stability, reliability), and did not appear to relate to commonly available global mental abilities. An off-the-shelf portable battery of temporal factors which stabilizes rapidly could have several important applications. First, individual differences in temporal acuity could be employed to improve job productivity to the extent that such abilities are at the basis of certain jobs and activities. Second, since time-course changes were evident with the tests, they can be used to study training implications of these temporal factors. Third, the results could be used to identify temporal aspects of visual displays for advancing understanding in engineering design.
The Rate of Gain of Perceived Workload in Sustained Attention
Authors: Dember William N. , Warm Joel S. , Nelson W. Todd , Simons Karen G. , Hancock Peter A. , Gluckman Jonathan P.
Published: April 2008

Perceived workload was measured via the NASA TLX following a visual vigilance task. Five task durations (10, 20, 30, 40, or 50 min) were combined factorially with two levels of discrimination difficulty (easy, hard) in a between groups design. Detection probability, computed from the final 10 min of watch in each duration condition, varied inversely with signal salience and declined over time. Overall workload varied directly with salience and increased linearly over time. The temporal growth in perceived workload was independent of signal salience. This result suggests that the rate of gain in workload is based upon general features of the vigilance situation rather than specific psychophysical demands such as signal salience.
Religion and Spirituality Along the Suicidal Path
Authors: Colucci Erminia , Martin Graham
Published: April 2008

The inner experience of spiritual and religious feelings is an integral part of the everyday lives of many individuals. For over 100 years the role of religion as a deterrent to suicidal behavior has been studied in various disciplines. We attempt to systematize the existing literature investigating the relationship between religion/spirituality and suicide in this paper. After an overview of the attitudes of the dominant religions (e.g., Catholicism, Islam, and Buddhism) toward suicide, the three main theories that have speculated regarding the link between religion and suicide are presented: “integration theory” (Durkheim, 1897/1997), “religious commitment theory” (Stack, 1983a; Stark, 1983), and “network theory” (Pescosolido & Georgianna, 1989). Subsequent to this theoretical introduction, we report on studies on religion/spirituality keeping the suicidal path as a reference: from suicidal ideation to nonlethal suicidal behavior to lethal suicidal behavior. Studies presenting indications of religious beliefs as a possible risk factor for suicidal behavior are also presented. The last section reviews possible intervention strategies for suicidal patients and suicide survivors. Indications for future research, such as more studies on nonreligious forms of spirituality and the use of qualitative methodology to achieve a better and deeper understanding of the spiritual dimension of suicidal behavior and treatment, are offered.
Targeting Adolescents' Literacy Skills Using One‐To‐One Instruction With Research‐Based Practices
Authors: Houge Timothy T. , Geier Constance , Peyton David
Published: April 2008

Although there is evidence that literacy deficiencies in adolescents can be remedied with one‐to‐one tutoring using research‐based instructional strategies, a review of current literature provides only limited information on transferring effective instructional strategies to learning environments outside of one‐to‐one tutoring centers. The authors of this article identify three components of successful one‐to‐one literacy tutoring programs, discuss what research reveals regarding one‐to‐one literacy instruction with adolescents, and provide commentary on how the instruction used in their reading clinic can be replicated for those attempting to apply one‐to‐one literacy instruction inside a tutoring center, resource room, or traditional classroom setting.
“Tomorrow Will Not be Like Today”: Literacy and Identity in a World of Multiliteracies
Authors: Williams Bronwyn T.
Published: April 2008

The speed with which the technologies of literacy are changing is dazzling and unsettling. Almost every year, it seems a new way of combining words, images, and video emerges and becomes a phenomenon among students. Meanwhile, teachers are left wondering how to respond to these new ways of writing and reading and the identities that students create through them. How should we teach in an age of electronic and global multiliteracies? What concepts and approaches can we identify that will be central to our teaching and important for our students no matter what the future brings?
Balancing the Assessment of Learning and for Learning in Support of Student Literacy Achievement
Authors: Edwards Patricia A. , Turner Jennifer D. , Mokhtari Kouider
Published: April 2008

There is a delicate balance between the assessment of learning and assessment for learning. The recommendations included in this Assessment department may be useful for teachers working to achieve this balance and find a more accurate and complete understandings of students' literacy strengths and needs.
Museum Literacies of a Second‐Grade Classroom
Authors: Eakle A. Jonathan , Dalesio Brooke L.
Published: April 2008

Concepts of museum literacies are introduced in this report. Information is presented for how museum literacies were initiated, designed, and produced in a second‐grade classroom. Findings show how participants took up museum literacies differently, including their uses of printed texts and other communicative forms. Two short case studies are presented that suggest how museum literacies can be engaging and transforming for students. Suggestions of how to use museum literacies are provided for educators, online museum resources are included. These practices suggest creative possibilities to teach literacies while covering subject area content and addressing school curricular standards.
Providing All Students ACCESS to Self‐Regulated Literacy Learning
Authors: Parsons Seth A.
Published: April 2008

ACCESS is an organizational framework to help educators plan instruction that prepares students for high‐stakes tests and promotes self‐regulated literacy learning. ACCESS stands for tasks that are authentic, that require collaboration among students, that challenge students, that culminate with an end product, that allow self‐direction by giving students choices, and that sustain learning across time. Each component of ACCESS supports self‐regulated literacy learning, and the framework can be incorporated into teachers' busy schedules.
Guiding Independence: Developing a Research Tool to Support Student Decision Making in Selecting Online Information Sources
Authors: Baildon Rindi , Baildon Mark
Published: April 2008

The development and use of a research tool to guide fourth‐grade students' use of information sources during a research project is described in this article. Over a period of five weeks, 21 fourth‐grade students in an international school in Singapore participated in a study investigating the extent to which the use of a “research resource guide” improved their independence in the research process. Findings indicate that students became more independent as a result of their use of the research guide. Students demonstrated greater consideration of a source's readability, trustworthiness, and usefulness when deciding whether to use it. The authors describe approaches to support students in making determinations about the readability, trustworthiness, and usefulness of sources of information.
Pourquoi Tales on the Literacy Stage
Authors: Foster Karen K. , Theiss Deb , Buchanan‐Butterfield Dawna Lisa
Published: April 2008

Since ancient times, humans have sought explanations for the mysteries of nature's beauty and variety. Like other kinds of folk stories, pourquoi tales can be considered parables about how humans and animals originated in the world or why they look or behave the way they do. This article briefly defines the characteristics of the genre and highlights active strategies for using them in the curriculum so that students can be “up front and center” on the literacy stage, performing through song, digital art, and drama.
Cracking in deep beams owing to shear loading. Part 1: Experimental study and assessment
Authors: Malm R. , Holmgren J.
Published: April 2008

In this paper, laboratory tests to failure of ten large deep beams with I-shaped cross-sections are presented. All beams had the same geometry with a shear span-to-depth ratio of 1·25 but differed in the amount of the vertical and horizontal web reinforcement. The presented results from the measurements consist of load–deformation curves, crack widths and crack patterns and strain distribution near the supports. The ultimate loads for these beams have been calculated with two strut-and-tie models and one truss model. The first strut-and-tie model calculates the tensile contribution of both reinforcement and concrete and takes into account their influence on the principal tensile stress. The second strut-and-tie model is a modification of the first one where the stress distribution along the strut is redefined. The third method is the truss model that is incorporated in a Design Code. The truss model gave the best result for the beams with a higher reinforcement ratio that exhibited in a shear compressive failure. The diagonal tensile failure that occurred in the beams with a small amount of web reinforcement was best captured with the modified strut-and-tie model.
Mercury correlations among six tissues for four waterbird species breeding in San Francisco Bay, California, USA
Authors: Eagles-Smith Collin A , Ackerman Joshua T , Adelsbach Terrence L , Takekawa John Y , Miles A. Keith , Keister Robin A
Published: April 2008

Despite a large body of research concerning mercury (Hg) in birds, no single tissue has been used consistently to assess Hg exposure, and this has hampered comparisons across studies. We evaluated the relationships of Hg concentrations among tissues in four species of waterbirds (American avocets [Recurvirostra americana], black-necked stilts [Himantopus mexicanus], Caspian terns [Hydroprogne caspia; formerly Sterna caspia], and Forster's terns [Sterna forsteri]) and across three life stages (prebreeding adults, breeding adults, and chicks) in San Francisco Bay, California, USA. Across species and life stages, Hg concentrations (least square mean ± standard error) were highest in head feathers (6.45 ± 0.31 μg/g dry wt) and breast feathers (5.76 ± 0.28 μg/g dry wt), followed by kidney (4.54 ± 0.22 μg/g dry wt), liver (4.43 ± 0.21 μg/g dry wt), blood (3.10 ± 0.15 μg/g dry wt), and muscle (1.67 ± 0.08 μg/g dry wt). Relative Hg distribution among tissues, however, differed by species and life stage. Mercury concentrations were highly correlated among internal tissues (r2 ≥ 0.89). Conversely, the relationships between Hg in feathers and internal tissues were substantially weaker (r2 ≤ 0.42). Regression slopes sometimes differed among species and life stages, indicating that care must be used when predicting Hg concentrations in one tissue based on those in another. However, we found good agreement between predictions made using a general tissue-prediction equation and more specific equations developed for each species and life stage. Finally, our results suggest that blood is an excellent, nonlethal predictor of Hg concentrations in internal tissues but that feathers are relatively poor indicators of Hg concentrations in internal tissues.
Influence of lake characteristics on the biomagnification of persistent organic pollutants in lake trout food webs
Authors: Houde Magali , Muir Derek C. G , Kidd Karen A , Guildford Stephanie , Drouillard Ken , Evans Marlene S , Wang Xiaowa , Whittle D. Michael , Haffner Doug , Kling Hedy
Published: April 2008

The biomagnification of polychlorinated biphenyls (PCBs) and major organochlorine pesticides (OCPs) was studied using lake trout (Salvelinus namaycush) and other food web organisms collected from 17 lakes in Canada and the northeastern United States between 1998 and 2001. Whole lake trout (n = 357) concentrations of the sum (Σ) of 57 PCB congeners ranged between 1.67 and 2,890 ng/g wet weight (median 61.5 ng/g wet wt). Slimy sculpin had the highest mean concentrations of ΣPCB of all forage fish (32–73 ng/g wet wt). Positive relationships between log (lipid wt) concentrations of PCB congener 153, PCB congener 52, p,p'-dichlorodiphenyldichloroethylene, hexachlorobenzene, cis-chlordane, trans-nonachlor, or dieldrin and trophic level (determined using stable nitrogen isotope ratios) were found for most of the 17 food webs, indicating biomagnification of these PCBs and OCPs. The p,p'-dichlorodiphenyldichloroethylene had the highest trophic magnification factors (TMFs) of the 14 individual compounds studied, averaging 4.0 ± 1.8 across the 17 lakes, followed by trans-nonachlor (3.6 ± 1.5) and PCB congener 153 (3.4 ± 1.2). Average TMFs for 14 individual PCBs or OCPs were significantly correlated with log octanol–water partition coefficient, implying that the rate of accumulation along the food web is dependent on hydrophobicity and recalcitrance. Significant correlations (p < 0.05) were found between TMFs of ΣPCBs, hexachlorobenzene, α-hexachlorocyclohexane, and lindane and lake area, latitude, and longitude, but not for 11 other PCBs or OCPs. Overall, the results of the present study show that biomagnification of PCBs and most OCPs, as measured by TMFs, is only weakly influenced by such factors as latitude and longitude. Exceptions are hexachlorocyclohexane isomers and hexachlorobenzene, which had generally greater TMFs in northern lakes, possibly due to lower rates of elimination and biotransformation in the food web.
Estimation of Successful Breeding Pairs for Wolves in the Northern Rocky Mountains, USA
Authors: MITCHELL MICHAEL S. , AUSBAND DAVID E. , SIME CAROLYN A. , BANGS EDWARD E. , GUDE JUSTIN A. , JIMENEZ MICHAEL D. , MACK CURT M. , MEIER THOMAS J. , NADEAU M. STEVEN , SMITH DOUGLAS W.
Published: April 2008

Abstract: Under the Endangered Species Act, documenting recovery and federally mandated population levels of wolves (Canis lupus) in the Northern Rocky Mountains (NRM) requires monitoring wolf packs that successfully recruit young. United States Fish and Wildlife Service regulations define successful breeding pairs as packs estimated to contain an adult male and female, accompanied by ≥2 pups on 31 December of a given year. Monitoring successful breeding pairs will become more difficult following proposed delisting of NRM wolves; alternatives to historically intensive methods, appropriate to the different ecological and regulatory context following delisting, are required. Because pack size is easier to monitor than pack composition, we estimated probability a pack would contain a successful breeding pair based on its size for wolf populations inhabiting 6 areas in the NRM. We also evaluated the extent to which differences in demography of wolves and levels of human‐caused mortality among the areas influenced the probability of packs of different sizes would contain successful breeding pairs. Probability curves differed among analysis areas, depending primarily on levels of human‐caused mortality, secondarily on annual population growth rate, and little on annual population density. Probabilities that packs contained successful breeding pairs were more uniformly distributed across pack sizes in areas with low levels of human mortality and stable populations. Large packs in areas with high levels of human‐caused mortality and high annual growth rates had relatively high probabilities of containing breeding pairs whereas those for small packs were relatively low. Our approach can be used by managers to estimate number of successful breeding pairs in a population where number of packs and their sizes are known. Following delisting of NRM wolves, human‐caused mortality is likely to increase, resulting in more small packs with low probabilities of containing breeding pairs. Differing contributions of packs to wolf population growth based on their size suggests monitoring successful breeding pairs will provide more accurate insights into population dynamics of wolves than will monitoring number of packs or individuals only.
Occupancy of Mountain Plover and Burrowing Owl in Colorado
Authors: TIPTON HEATHER C. , DREITZ VICTORIA J. , DOHERTY PAUL F.
Published: April 2008

Abstract: Concern over the decline of grassland birds has spurred efforts to increase understanding of grassland bird‐habitat relationships. Previous studies have suggested that black‐tailed prairie dogs (Cynomys ludovicianus) provide important habitat for shortgrass prairie avifauna, such as mountain plover (Charadrius montanus) and western burrowing owl (Athene cunicularia hypugaea), although such studies are lacking in Colorado (USA). We used methods to estimate occupancy (ψ) of mountain plover and burrowing owl on prairie dog colonies and other shortgrass prairie habitats in eastern Colorado. Mountain plover occupancy was higher on prairie dog colonies (ψ = 0.50, 95% CI = 0.36–0.64) than on grassland (ψ = 0.07, 95% CI = 0.03–0.15) and dryland agriculture (ψ = 0.13, 95% CI = 0.07–0.23). Burrowing owl occupancy was higher on active prairie dog colonies (ψ = 0.80, 95% CI = 0.66–0.89) compared with inactive colonies (ψ = 0.23, 95% CI = 0.07–0.53), which in turn was much higher than on grassland (ψ = 0.01, 95% CI = 0.00–0.07) and dryland agriculture (ψ = 0.00, 95% CI ψ 0.00–0.00). Mountain plover occupancy also was positively correlated with increasing amounts of prairie dog colony in the landscape. Burrowing owl occupancy was negatively correlated with increasing amounts of prairie dog colony in the surrounding landscape. Our results suggest that actions to conserve mountain plovers and burrowing owls should incorporate land management to benefit prairie dogs. Because managing for specific colony attributes is difficult, alternative management that promotes heterogeneity may ensure that suitable habitat is available for the guild of grassland inhabitants.
One‐Sided Barrier Impact of an International Railroad on Mongolian Gazelles
Authors: ITO TAKEHIKO Y. , OKADA AYUMI , BUUVEIBAATAR BAYARBAATAR , LHAGVASUREN BADAMJAV , TAKATSUKI SEIKI , TSUNEKAWA ATSUSHI
Published: April 2008

Abstract: We conducted a carcass census of Mongolian gazelles (Procapra gutturosa) along the Trans‐Mongolian railroad in June 2005. We counted 241 gazelles that had died within the previous 12 months. Carcass numbers were greater on the southwestern side in the northern 3 zones, but we found carcasses only on the northeastern side in the southernmost zone. It suggests that impact of the railroad was stronger on one side and that the strength of this impact varied among regions.