Showing papers by "Boise State University published in 2004"
TL;DR: Climate records from high latitudes, subtropical regions and the tropics are compared, indicating that the onset of large glacial/interglacial cycles did not coincide with a specific climate reorganization event at lower latitudes and suggesting that mean low-latitude climate conditions can significantly influence global climate feedbacks.
Abstract: The Earth's climate has undergone a global transition over the past four million years, from warm conditions with global surface temperatures about 3 °C warmer than today, smaller ice sheets and higher sea levels to the current cooler conditions. Tectonic changes and their influence on ocean heat transport have been suggested as forcing factors for that transition, including the onset of significant Northern Hemisphere glaciation ∼2.75 million years ago, but the ultimate causes for the climatic changes are still under debate. Here we compare climate records from high latitudes, subtropical regions and the tropics, indicating that the onset of large glacial/interglacial cycles did not coincide with a specific climate reorganization event at lower latitudes. The regional differences in the timing of cooling imply that global cooling was a gradual process, rather than the response to a single threshold or episodic event as previously suggested. We also find that high-latitude climate sensitivity to variations in solar heating increased gradually, culminating after cool tropical and subtropical upwelling conditions were established two million years ago. Our results suggest that mean low-latitude climate conditions can significantly influence global climate feedbacks.
615 citations
TL;DR: It is demonstrated that tau is cleaved at D421 (DeltaTau) by executioner caspases, and therapeutics aimed at inhibiting tau caspase-cleavage may prove beneficial not only in preventing NFT formation, but also in slowing cognitive decline.
Abstract: Neurofibrillary tangles (NFTs) are composed of abnormal aggregates of the cytoskeletal protein tau. Together with amyloid β (Aβ) plaques and neuronal and synaptic loss, NFTs constitute the primary pathological hallmarks of Alzheimer disease (AD). Recent evidence also suggests that caspases are activated early in the progression of AD and may play a role in neuronal loss and NFT pathology. Here we demonstrate that tau is cleaved at D421 (ΔTau) by executioner caspases. Following caspase-cleavage, ΔTau facilitates nucleation-dependent filament formation and readily adopts a conformational change recognized by the early pathological tau marker MC1. ΔTau can be phosphorylated by glycogen synthase kinase-3β and subsequently recognized by the NFT antibody PHF-1. In transgenic mice and AD brains, ΔTau associates with both early and late markers of NFTs and is correlated with cognitive decline. Additionally, ΔTau colocalizes with Aβ1–42 and is induced by Aβ1–42 in vitro. Collectively, our data imply that Aβ accumulation triggers caspase activation, leading to caspase-cleavage of tau, and that this is an early event that may precede hyperphosphorylation in the evolution of AD tangle pathology. These results suggest that therapeutics aimed at inhibiting tau caspase-cleavage may prove beneficial not only in preventing NFT formation, but also in slowing cognitive decline.
516 citations
Journal Article•
TL;DR: The physiological responses in this study were less severe during a MS test than those reported during an incremental Balke treadmill test, and suggests that MS tests may be an acceptable method to assess the maximal strength of patients with moderate heart failure.
Abstract: An experiment was designed to determine if Kinesio™ taping the anterior and lateral portion of the ankle would enhance ankle proprioception compared to the untaped ankle. 30 subjects, 15 men, 15 women, ages 18-30 participated in this study. Exclusion criteria: Ankle injury < 6 months prior to testing, significant ligament laxity as determined through clinical evaluation by an ATC, or any severe foot abnormality. Experiment utilized a single group, pretest and posttest. Plantar flexion and inversion with 20° of plantar flexion reproduction of joint position sense (RJPS) was determined using an ankle RJPS apparatus. Subjects were barefooted, blindfolded, and equipped with headphones playing white noise to eliminate auditory cues. Subjects had five trials in both plantar flexion and inversion with 20° plantar flexion before and after application of the Kinesio™ tape to the anterior/lateral portion of the ankle. Constant error and absolute error were determined from the difference between the target angle and the trial angle produced by the subject. The treatment group (Kinesio™ taped subjects) showed no change in constant and absolute error for ankle RJPS in plantar flexion and 20° of plantar flexion with inversion when compared to the untaped results using the same motions. The application of Kinesio™ tape does not appear to enhance proprioception (in terms of RJPS) in healthy individuals as determined by our measures of RJPS at the ankle in the motions of plantar flexion and 20° of plantar flexion with inversion.
Key Points
Proprioception research
Evaluation of a new taping method
Augmentation of sensory feedback
Rehabilitation technique
287 citations
TL;DR: For each space, U fin (Γ, Ω) is equivalent to S fin(Ω, O wgp ) and this selection property has game-theoretic and Ramsey-theory characterizations (Theorem 2) as discussed by the authors.
179 citations
TL;DR: In this paper, a mechanism for mathematics conceptual learning that can serve as a basis for the design of mathematics lessons is presented. But it does not address the learning paradox, a paradox that derives from careful attention to the construct of assimilation.
Abstract: We articulate and explicate a mechanism for mathematics conceptual learning that can serve as a basis for the design of mathematics lessons. The mechanism, reflec- tion on activity-effect relationships, addresses the learning paradox (Pascual-Leone, 1976), a paradox that derives from careful attention to the construct of assimilation (Piaget, 1970). The mechanism is an elaboration of Piaget's (2001) reflective abstrac- tion and is potentially useful for addressing some of the more intractable problems in teaching mathematics. Implications of the mechanism for lesson design are discussed and exemplified.
174 citations
Journal Article•
TL;DR: The authors found that students in psychology courses read on average 27.46% of the assigned readings before class and 69.98% before an exam, with significant differences existing between courses.
Abstract: Knowing that the study strategies of students using college textbooks can be a powerful predictor of performance in the classroom, we examined the extent to which students in different psychology courses reported reading their textbooks. In psychology courses overall, students read on average 27.46% of the assigned readings before class and 69.98% before an exam, which corresponds to previous research. We furthermore found that these percentages were highly influenced by the course in which the students responded. In fact the percentages ranged from 21.21% to only 42.96% before class and from 60.83% to 91.20% before an exam, with significant differences existing between courses. Given that the majority of college students spend less than 3 hours reading textbook material and that they feel the instructor is responsible for reviewing material during class time, as well as, telling them what is important in the reading, instructors must find ways to encourage more reading by students, even if this involves giving quizzes over reading material. ********** Reading educators, when focusing on a student's skills and difficulties in learning from textbooks, have found that college freshmen lack mature and efficient strategies necessary for learning on their own (Simpson, 1984 as cited in Wandersee, 1988). Throughout the study, Simpson found that college freshmen had minimal strategies for studying, did not know why they chose a particular strategy, and were uncertain in how to determine if they were prepared for an exam. Friedman and Wilson (1975) indicated that considerable efforts have been made to improve how students learn, but little attention has been paid to the core element of that process, which is how students read their textbooks. As evidence of this Friedman and Wilson found when students were presented unknowingly with textbooks containing glue seals throughout the textbook chapters, the students spent more time reading chapter summaries rather than the chapters themselves when preparing for an examination. Thus, students cannot be involved in the type of meaningful learning that Wandersee described, in which a student must find the meaning the author presents, decide its significance, learn the meaning, relate the concept to past experiences in order to clarify it, and continue to practice and review what was learned from the textbook material. This level of learning cannot take place by merely reading the chapters summaries in a textbook. Smith (1982) found the learning strategies of mature learners involve not only reading their textbooks, but they also find alternatives texts to aid them in their knowledge acquisition, which is in stark contrast to those only reading chapter summaries. Wandersee (1988) stated that reading leads to better grades, which would lead one to assume that students would read their textbooks in order to prepare for examinations. However, Burchfield and Sappington (2000) found an overall decline in reading compliance over a 16 year span. Furthermore, Sikorski et al. (2002) found that most students reported reading their textbooks less than 3 hours per week, which is significantly less than university recommendations for study regimens, which commonly advise at least 2 hours of study time for every class credit (The Center for Advancement of Learning, 1998). For example, if a class meets for 3 hours a week, students should plan to spend at least 6 hours studying that subject each week. If a student has 15 class hours every week, he/she should spend at least 30 hours studying per week. The idea is that students need to treat college like a full-time job, meaning class preparation should take approximately 40 hours a week, but only 12 percent of college freshmen spend 26 hours or more a week studying, and most spend less than 15 hours a week studying (Indiana University Center for Postsecondary Research and Planning, 2002). In addition George Kuh (in Young, 2002) stated that "students are studying about one-third as much as faculty say they ought to, to do well" (p. …
168 citations
TL;DR: Examination of peak vertical impact forces and rate of force development following a plyometric-based knee ligament injury prevention program indicates that 9 weeks of KLIP training altered landing strategies in women to lower Fp and RFD, considered conducive to a reduced risk of knee injury while landing.
Abstract: Previous research suggests high impact forces generated during landings contribute to noncontact anterior cruciate ligament (ACL) injuries. In women, neuromuscular differences appear to modify the ability to dissipate landing forces when compared to men. This study examined peak vertical impact forces (F(p)) and rate of force development (RFD) following a 9-week, low-intensity (simple jump-landing-jump tasks) and volume (number of foot contacts per workout) plyometric-based knee ligament injury prevention (KLIP) program. Female subjects were randomly assigned into control (n = 14) and treatment (n = 14) groups. Treatment subjects attended KLIP sessions twice a week for 9 weeks, and control subjects received no intervention. Ground reaction forces (F(p) and RFD) generated during a step-land protocol were assessed at study onset and termination. Significant reductions in F(p) (p = 0.0004) and RFD (p = 0.0205) were observed in the treatment group. Our results indicate that 9 weeks of KLIP training altered landing strategies in women to lower F(p) and RFD. These changes are considered conducive to a reduced risk of knee injury while landing.
165 citations
TL;DR: In this article, a multivariate statistical technique, known as k-means cluster analysis, is used to correlate and integrate information contained in velocity and attenuation tomograms, and a comparison of the clustered tomographic section with well-log data demonstrates that their approach delineates the hydrostratigraphic zonation.
Abstract: [1] We have investigated the potential of combining cross-hole georadar velocity and attenuation tomography as a method for characterizing heterogeneous alluvial aquifers. A multivariate statistical technique, known as k-means cluster analysis, is used to correlate and integrate information contained in velocity and attenuation tomograms. Cluster analysis allows us to identify objectively the major common trends in the tomographic data and thus to “reduce” the information to a limited number of characteristic parameter combinations. The application of this procedure to two synthetic data sets indicates that it is a powerful tool for converting the complex relationships between the tomographically derived velocity and attenuation structures into a lithologically and hydrologically meaningful zonation of the probed region. In addition, these synthetic examples allow us to evaluate the reliability of further petrophysical parameter estimates. We find that although absolute values of the tomographically inferred petrophysical parameters often differ significantly from the actual parameters, the clustering approach enables us to reliably identify the major trends in the petrophysical properties. Finally, we have applied the approach to a cross-hole georadar data set collected in a well-studied alluvial aquifer. A comparison of the clustered tomographic section with well-log data demonstrates that our approach delineates the hydrostratigraphic zonation.
131 citations
05 Jan 2004
TL;DR: Thirteen specific privacy issues are enumerated and discussed as examples of the challenges the authors face as these technologies and their associated products and services are deployed.
Abstract: Location awareness, the ability to determine geographical position, is an emerging technology with both significant benefits and important privacy implications for users of mobile devices such as cell phones and PDAs. Location is determined either internally by a device or externally by systems and networks with which the device interacts, and the resultant location information may be stored, used, and disclosed under various conditions that are described. Thirteen specific privacy issues are enumerated and discussed as examples of the challenges we face as these technologies and their associated products and services are deployed. Regulation by governments, standards organizations, industry groups, public interest groups, and marketplace forces are discussed as it may help address privacy issues.
122 citations
TL;DR: An overview of the historical development of augmentation and alternative communication (AAC) services can be found in this article, tracing their evolution over the past half-century through four specific themes: social change and legislation, assessment, intervention and family and cultural issues.
Abstract: Augmentative and alternative communication (AAC) is a prominent component in the development of support services for individuals with disabilities, especially those with severe disabilities. In this article we provide an overview of the historical development of AAC services, tracing their evolution over the past half-century through four specific themes: social change and legislation, assessment, intervention, and family and cultural issues.
105 citations
TL;DR: In this paper, the spatial variability of over a 2 year period, and related changes in temporally stable soil water patterns to stream flow generation were characterized in a 0.36 km 2 headwater catchment.
Abstract: Soil is a critical intermediary of water flux between precipitation and stream flow. Characterization of soil water content (� ,m 3 m � 3 ) may be especially difficult in mountainous, snow-dominated catchments due to highly variable water inputs, topography, soils and vegetation. However, individual sites exhibit similar seasonal dynamics, suggesting that it may be possible to describe spatial variability in terms of temporally stable relationships. Working in a 0Ð36 km 2 headwater catchment, we: (i) described and the spatial variability ofover a 2 year period, (ii) characterized that variability in terms of temporal stability analysis, and (iii) related changes in temporally stable soil water patterns to stream flow generation. Soil water data were collected for 2 years at representative sites and quantified in terms of � and water storage to a depth of 75 cm (S75, cm). Both S75 andwere normally distributed in space on all measurement dates. Spatial variability was high relative to other studies, reflecting catchment heterogeneity. However, the ranking of S75 values displayed temporal stability for all site locations, seasonally and annually. This stability was attributed to soil texture. Further temporal analysis indicated that estimates of catchment mean and standard deviation of S75 may be characterized with relatively few measurements. Finally, we used temporal linear regression to define catchment soil water conditions related to stream-flow generation. Static, high S75 conditions in late winter and early spring indicate that stream-flow response is highly sensitive to inputs, whereas static, low S75 conditions in late summer and early fall indicate minimum stream-flow sensitivity to water inputs. The fall transition was marked by uniform S d across the catchment. The late spring transition was marked by nonuniform S75 decreases, with the highest S75 sites decreasing most. Threshold S75 values identifying catchment sensitivity to water input were identified. Copyright 2004 John Wiley & Sons, Ltd.
TL;DR: In this paper, the Campbell Scientific water content reflectometer (WCR) was used for field-calibrated volumetric soil water content (VWC) measurement and a linear correlation between the WCR measured period and TDR-measured VWC was found.
Abstract: Field monitoring of volumetric soil water content (VWC) is critical for a variety of applications. Recently developed electronic soil water sensors provide a relatively inexpensive monitoring option. However, the calibration of these sensors is more sensitive to variations in soil properties than for time domain reflectometry (TDR), which is generally regarded as the best electronic means of VWC measurement and which has a relatively robust calibration. Field calibration incorporates the effects of within-profile and between-site soil variations and individual variability on sensor response. The objective of this study was to evaluate the effectiveness of using TDR to field-calibrate the Campbell Scientific water content reflectometer (WCR), or CS-615, which is an example of a newly developed sensor in widespread use. We found that (i) there was a strong, linear correlation between the WCR-measured period and TDR-measured VWC; (ii) the WCR calibration varied with soil type; (iii) calibration of individual sensors resulted in excellent agreement between TDR and the WCR measurements; and (iv) calibration resulted in improved description of soil water dynamics and improved precision of VWC estimates.
TL;DR: In this article, the effects of buyer satisfaction with the adoption of technology-mediated communication (STMC) on channel partner relationships were examined and shown to have significant, positive, direct effects on future intentions (FI).
TL;DR: In this paper, three late Paleozoic, angular unconformities, each tightly constrained in age by biostratigraphy, are exposed in Carlin Canyon, Nevada.
Abstract: Three late Paleozoic, angular unconformities, each tightly constrained in age by biostratigraphy, are exposed in Carlin Canyon, Nevada. These record deformation as well as erosion. Folding associated with these deformation events is roughly coaxial; all three sets of fold axes trend northeast. Each unconformity represents tectonic disruption of the middle part of the western North American margin between the times of the initiation of the Antler orogeny (Late Devonian–Early Mississippian) and the Permian–Triassic Sonoma orogeny. This paper focuses on one of these unconformities in the Middle Pennsylvanian—the C6 unconformity—and the deformation and age constraints associated with it.
Our data from Carlin Canyon yield detailed glimpses of how the Antler foreland evolved tectonically in Mississippian and Pennsylvanian time. Middle Pennsylvanian (Desmoinesian) northwest-southeast contraction resulted in thin-skinned folding and faulting, uplift, and erosion. These data require reinterpretation of the tectonic setting at the time of the Ancestral Rocky Mountains orogeny and suggest that plate convergence on the west side of the continent played a significant role in late Paleozoic tectonics of the North American continent.
TL;DR: In this article, the authors compare turnover rates in states with and without term limits and find that turnover rates, overall, continued to decline through the 1980s but that the long downward trend abated in the 1990s as a result of term limits.
Abstract: Increases in legislative professionalization along with the implementation of term limits in about one-third of the American states raise significant questions about the path of state house and senate turnover. We first update turnover figures for all states, by chamber, from the mid-1980s through 2002. We then compare turnover rates in states with and without term limits. We find that turnover rates, overall, continued to decline through the 1980s but that the long downward trend abated in the 1990s as a result of term limits. The effects of term limits vary depending on the length of the term limit and the opportunity structure in the state. There is also a strong relationship between the presence of term limits and interchamber movement. In addition to term limits, professionalization levels, redistricting, the presence of multi-member districts, and partisan swings explain differences in turnover rates between states.
TL;DR: In this article, a multi-variate model is proposed that implicates attitude, affect, past behavior, and perceived control as predictors of intention to maintain a financial budget.
TL;DR: My efforts to improve student skills in solving unstructured problems in a junior-level undergraduate business course by employing a problem-based learning (PBL) design are described and a 7-step problem-solving model is presented.
Abstract: This article describes my efforts to improve student skills in solving unstructured problems in a junior-level undergraduate business course by employing a problem-based learning (PBL) design. A rationale for adopting a PBL approach for this course is articulated. A 7-step problem-solving model is then presented. The course’s design is described, including its learning outcomes, PBL projects, associated learning activities, and methods of assessing learning. Finally, student reactions and evidence of learning are discussed. The article concludes by raising a related issue: If graduates possess skills in solving unstructured problems, will businesses be receptive to their use?
TL;DR: In this paper, the authors report on the findings of a Delphi study conducted to determine research needs in educational technology over the next five years and provide a framework of eight research priority areas and specific research topics for those engaged in education technology.
Abstract: This article reports on the findings of a Delphi study conducted to determine research needs in educational technology over the next five years. The Delphi panel consisted of 30 educational technology experts from throughout the United States who participated in a three-round consensus building process via the Internet. The results of this e-research study provide a framework of eight research priority areas and specific research topics for those engaged in educational technology. (Keywords: research priorities, learning, teachers, models, strategies.)
TL;DR: In this paper, changes in the magnetic properties of ferrihydrite (FHYD) nanoparticles (formula $\rm{FeOOH}\ensuremath{\cdot}n{\mathrm{H}}_{2}\Mathrm{O};$ $\mathrm{\simeq}5\mathm{nm})$ on doping with 5 at. % each of Ni, Mo and Ir by coprecipitation are reported.
Abstract: In this work, changes in the magnetic properties of ferrihydrite (FHYD) nanoparticles (formula $\mathrm{FeOOH}\ensuremath{\cdot}n{\mathrm{H}}_{2}\mathrm{O};$ $\mathrm{size}\ensuremath{\simeq}5\mathrm{nm})$ on doping with 5 at. % each of Ni, Mo, and Ir by coprecipitation are reported. The variations of magnetization M as a function of magnetic field H (up to \ifmmode\pm\else\textpm\fi{}50 kOe) and temperature T (5--375 K) were investigated for the four samples, viz., FHYD, Ni/FHYD, Mo/FHYD, and Ir/FHYD, both for the zero-field-cooled (ZFC) and field-cooled (FC) conditions. The T variation of the low-field $(H=100\mathrm{Oe})$ magnetic susceptibility \ensuremath{\chi} (ZFC) peaks at temperature ${T}_{p}\ensuremath{\simeq}70,$ 47, 43, and 34 K for FHYD, Ni/FHYD, Mo/FHYD, and Ir/FHYD, respectively. For $Tl{T}_{p},$ \ensuremath{\chi} $(\mathrm{ZFC})l\ensuremath{\chi}$ (FC), and \ensuremath{\chi} (FC) shows broad minima at ${T}_{s}=30,$ 27, 22, and 16 K for FHYD, Ni/FHYD, Mo/FHYD, and Ir/FHYD, respectively. The data are analyzed in terms of the modified Langevin function ${M=M}_{0}\mathcal{L}({\ensuremath{\mu}}_{p}H/kT)+{\ensuremath{\chi}}_{a}H,$ where ${\ensuremath{\mu}}_{p}$ is the magnetic moment/particle and k is the Boltzmann constant. From the analysis of the data, temperature-independent ${\ensuremath{\mu}}_{p}=369,$ 375, 237, and $239{\ensuremath{\mu}}_{B}$ are determined for FHYD, Ni/FHYD, Mo/FHYD, and Ir/FHYD, respectively. It is argued that the decrease in ${T}_{p}$ and ${T}_{s}$ noted above with doping results from shape anisotropy due to demagnetization fields. For $Tl~{T}_{s},$ the presence of exchange anisotropy may indicate spin-glass-like ordering of the surface spins. In this temperature regime, a steplike magnetization reversal behavior is observed in the low-field region of the hysteresis loops, in qualitative agreement with the theoretical predictions by Fraerman et al. [Phys. Rev. B 65, 184433 (2002)] for magnetic nanoparticles with interparticle interaction. Finally, from the observed magnitude of ${\ensuremath{\mu}}_{p},$ it is inferred that Ni substitutes for Fe throughout the nanoparticle, whereas doping with Mo and Ir occurs primarily at the surface.
TL;DR: In this article, a sociocultural perspective on teacher learning was used to investigate how three beginning teachers' conceptions of classroom management affected their developing teaching practices, and the implications of these findings for teacher education are discussed.
TL;DR: In this article, motion-sensing radio transmitters were implanted in cobbles and placed in a stream in south-west Idaho for 43 days during a snowmelt period.
Abstract: Motion-sensing radio transmitters were implanted in cobbles (72–92 mm diameter) and placed in a stream in south-west Idaho for 43 days during a snowmelt period. The radios transmit different pulse rates depending on whether the rocks are at rest or in motion. Every 30 s, a datalogger samples the receiver and records the pulse rate of the transmitters. Such information can be used to assess numerous properties of particle transport that are beyond the capabilities of conventional tracking methods. Conclusions include: (i) rocks are more likely to move on rising hydrograph limbs than on falling hydrograph limbs; (ii) the average Shields' parameter is 0·046; (iii) rocks move only a fraction of the time between initial and final motion during an event; (iv) the distributions of motion and rest periods are best modeled by gamma functions rather than exponential, but the distributions approach exponential as the tails are trimmed. Copyright © 2004 John Wiley & Sons, Ltd.
TL;DR: Caregiver-related need variables play a significant role in defining utilization patterns of community-based long-term care services among older adults, and their contribution to service use is examined.
Abstract: Objective: This study examined concurrent and long-term associations between caregiver-related characteristics and the use of community long-term care services in a sample of 186 older adults caring for a disabled spouse. Method: We used two waves of data from the Caregiver Health Effects Study, an ancillary study of the Cardiovascular Health Study. Caregiver-related need variables as predictors of service use were of primary interest and included caregiving demands, caregiver mental and physical health, and mastery. Their contribution to service use was examined after controlling for known predictors of service use. Results: At Time 1, more caregiver depressive symptoms predicted greater service use; at Time 2, more caregiver activity restriction and depressive symptoms predicted greater formal service use; increases in caregiver activity restriction and depressive symptomatology over time predicted increases in service use. Discussion: Caregiver-related need variables play a significant role in defining...
TL;DR: The authors investigated the degree to which elevated social status may lessen negative expectations of gender-token women assigned to leadership positions in male-dominated work groups and found that increased social status might help prevent gender token women from developing negative expectations about interactions with male dominated work groups.
Abstract: Prior research has shown that women report mostly negative expectations about being a gender-token in male-dominated work groups. We speculate that this is partially caused by the socially ascribed status devaluation of women. In this study we investigated the degree to which elevated social status may lessen negative expectations of gender-token women assigned to leadership positions. Sixty-three undergraduate women participated in 1 of 3 tokenism conditions: (1) nontoken, (2) gender-token, and (3) high-status gender-token. In all conditions participants were led to believe that they would be leading a group of men in a decision-making exercise. Leader expectations were then assessed. The results suggest that increased social status may help prevent gender-token women from developing negative expectations about interactions with male-dominated work groups.
TL;DR: Results suggest that Latino youths with no prior history of alcohol consumption remain largely unaffected by these acculturation-related variables and binge drinking behavior among nationally representative samples of Mexican American, Cuban American, and Puerto Rican youth.
Abstract: This research examined the relationship between acculturation-related variables and binge drinking behavior among nationally representative samples of Mexican American, Cuban American, and Puerto Rican youth. It explored the relationship between length of residence in the United States, type of language spoken in the home (Spanish vs. English) and binge drinking in each of these subgroups. Results suggest that Latino youths with no prior history of alcohol consumption remain largely unaffected by these acculturation-related variables. Youth with a previous history of alcohol consumption experience greater likelihood of binge drinking as a function of the acculturation-related variables, but the relationships are complex.
TL;DR: In this article, porosity data from well logs and grain-size distribution (GSD) data from core was used to investigate four pebble and cobble-dominated units that have been identified in porosity logs in deposits at a research well field (Boise Hydrogeophysical Research Site).
Abstract: Recognition and quantitative characterization of subsurface stratigraphic units in coarse unconsolidated fluvial deposits are difficult because large grain size and the large scale of sedimentary structures make direct interpretation from core difficult or impossible. In this paper, we use porosity data from well logs and grain-size distribution (GSD) data from core to investigate four pebble- and cobble-dominated units that have been identified in porosity logs in deposits at a research well field (Boise Hydrogeophysical Research Site). Lacking direct observation at an appropriate scale, questions about distribution of parameters and textural composition in these units are analyzed with statistical tests. The four pebble- and cobble-dominated “porosity stratigraphic” units may be grouped into two types: (1) Units 1 and 3 have low porosity (mean ∼0.17–0.18) and low porosity variance; and (2) Units 2 and 4 have higher porosity (mean ∼ 0.23–0.24) and higher porosity variance. Based on GSD data, core samples are subdivided into five lithotypes. The five lithotypes occur in different proportions and have different vertical transition probability characteristics in the two types of units: (1) Units 1 and 3 have only framework-gravel–dominated lithotypes and have random vertical transition probability between these two lithotypes; and (2) Units 2 and 4 consist of both framework-gravel–dominated and sand- or matrix-dominated lithotypes and have structured vertical transition probability. The two framework-gravel–dominated lithotypes occur in all four stratigraphic units but have distinctly lower porosity in Units 1 and 3 (i.e., tighter packing) than in Units 2 and 4 (looser packing). Considering the repeated stratigraphic occurrence of (and the statistical significance of differences between) the two types of units, both the individual unit distinctions and the two unit groupings appear to be valid. It is reasonable to interpret that the observed packing differences associated with Units 1 and 3 compared with Units 2 and 4 are related to different sedimentary processes that produce different bedforms or grain fabrics, perhaps under different bedload transport rates.
TL;DR: McConnell medial glide taping resulted in significant medial glide of the patellofemoral joint at all 4 knee angles before but not after exercise, however, it may be effective under controlled rehabilitation conditions in which exercise is less intense.
Abstract: Background: The authors assessed the effectiveness of McConnell medial glide taping after exercise using an MRI extremity scanner.Hypothesis: McConnell taping would not be effective in maintaining medial glide of the patella after exercise.Methods: Eighteen healthy women (mean age 22.28 ± 2.02 years) participated in the study. The patellofemoral joint was imaged at 4 knee flexion angles (0°, 12°, 24°, and 36°) in 3 conditions (no tape, with McConnell taping–medial glide, and with tape after exercise). Effectiveness was determined by measuring lateral patellar displacement. ANOVA and post hoc paired ttests were used to test for changes in lateral patellar displacement at each knee angle and condition.Results: Statistical analysis revealed significant differences in lateral patellar displacement at all test angles, between the tape and no tape and between tape and tape after exercise conditions.Conclusions: McConnell medial glide taping resulted in significant medial glide of the patellofemoral joint at all...
TL;DR: The data suggests that, for protocols with equated acute program variables, strength gain is similar over 18 weeks for training intensities ranging from 6 to 15 RM in previously untrained older adults.
Abstract: This study examined how training intensity affects
strength gains in older adults over an 18-week training period
using nonperiodized, progressive resistance-training protocols.
Untrained men and women participants were separated into 4
groups: group A (n = 17, 71.4 +- 4.6 years) performed 2 sets of
15 repetitions maximum (RM), group B (n = 13, 71.5 +- 5.2
years) performed 3 sets of 9 RM, group C (n = 17, 69.4 +- 4.4
years) performed 4 sets of 6 RM, group D (n = 14, 72.3 +- 5.9
years) served as controls. Training groups exercised 2 days/week
performing 8 resistance exercises. Except for training intensity,
the acute program variables were equated between groups. A
1RM for 8 exercises was obtained every 6 weeks. The total of
1RM for the 8 exercises served as the dependent variable. Results:
repeated measures analysis of variance (ANOVA) and
Scheffe post hoc revealed that, at 6 weeks, only groups B and C
were significantly stronger than group D (p < 0.01). By weeks
12 and 18, all training groups were significantly stronger than
controls (p < 0.01). However, no difference existed between
groups A, B, and C at any time. The data suggests that, for
protocols with equated acute program variables, strength gain
is similar over 18 weeks for training intensities ranging from 6
to 15 RM in previously untrained older adults. When programming
nonperiodized, progressive resistance exercise for novice
senior lifters, in the initial phases of the program, a wide range
of intensities may be employed with similar strength gain.
TL;DR: In this paper, Stratigraphic data from 63 Deep Sea Drilling Project and Ocean Drilling Program (ODP) sites that sample the lower Neogene and Paleogene sediments of the tropical Pacific have been compiled and put on the biostratigraphic and paleomagnetic timescale refined by ODP Leg 199 scientists.
Abstract: [1] Stratigraphic data from 63 Deep Sea Drilling Project and Ocean Drilling Program (ODP) sites that sample the lower Neogene and Paleogene sediments of the tropical Pacific have been compiled and put on the biostratigraphic and paleomagnetic timescale refined by ODP Leg 199 scientists. Sediment accumulation rates have been calculated for ten intervals ranging in age from 10 to 56 Ma and have been plotted for the midpoint of each interval at the associated paleoposition for each site used. A fixed hot spot model was used for reconstruction of the Pacific lithospheric plate. All such reconstructed intervals show the development of a tongue of high accumulation rates associated with the oceanographic divergence at the geographic equator. The development of this equatorial band is weakest between 46 and 56 Ma, the time of the peak warmth in Paleogene climate. Possible motion of the Hawaiian hot spot or true polar wander between 46 and 56 Ma appears to have had little effect on the plate rotation estimate of the position of the equator. In addition to temporal changes in the calcite compensation depth and in productivity, the biggest change in the patterns of sediment accumulation rates in the eastern tropical Pacific was the development of a relatively strong divergence between 6° and 10°N, near the region of divergence between the modern North Equatorial Current and the North Equatorial Counter Current. Changes in the equatorial circulation appear to be associated in time with the opening and closing of oceanic gateways, particularly the complex closing of the Caribbean-Pacific gateway.
TL;DR: In this article, the authors examined the recovery of biological soil crusts on sagebrush steppe following wildfire and showed that seeding is necessary to facilitate recovery of soil crust and hasten the development of the perennial component of the shrubland and increase landscape structure.
Abstract: Invasion of sagebrush steppe by exotic annual grasses has modified the structure of shrubland communities over much of the western United States by increasing fuel loads and therefore the frequency of wildfire. Active revegetation with perennial species that encourage the growth of biological soil crusts is critical on many burned sites to prevent dominance by exotic, weedy vegetation. However, active regeneration is likely to lead to a disruption of the soil surface and impact adversely on soil crust communities which are important for stability and functioning of shrub communities. We examined the recovery of biological soil crusts on sagebrush steppe following wildfire. Burning resulted in significantly reduced shrub cover and enhanced annual grass and annual forb cover compared with unburned sites. Burning also resulted in substantially reduced diversity and richness of crust taxa, increased cover of short mosses, but reduced cover of lichens and tall mosses growing on the shrub hummocks. Post-fire recovery of perennial grasses and biological soil crusts was greatest on seeded sites compared with unseeded sites dominated by exotic grasses, despite the disturbance associated with the rangeland seeding treatment. Our results indicate that seeding is necessary to facilitate recovery of biological soil crusts and hasten the development of the perennial component of the shrubland and therefore increase landscape structure. These findings suggest that seeding perennial grasses and resting from livestock grazing reduces exotic annual grasses after fire and benefits native mosses.
TL;DR: An action of caspase-3 involving cell dispersion that is independent of cell death is described and represents a novel role for caspases that may allow for proper migration of neurons to target locations during development.