bluuebunny/crossref_metadata_2025 huggingface dataset:
Plague Times: Scientific Internationalism and the Manchurian Plague of 1910/1911
Authors: Knab Cornelia
Published: March 2012

Among epidemic diseases, plague is particularly charged with historical memory and ominous cultural connotations. In many parts of the world, plague's seemingly mysterious origins, its gruesome ways of spreading, and its powers of devastation have raised it to a symbol of evil. In several languages, the word “plague” itself has become synonymous with scourge and universal disaster over the centuries. However, plague is not only a disease from the remote past; it also exemplifies the biological globalisation of modern times, highlighting at once socio-biological phenomena, global connectedness, and other dimensions of modernity. In particular, outbreaks of the so-called third plague pandemic from the late nineteenth to the mid-twentieth century made the disease an oppressive reality in many regions of the world.
A SINGLE-INDEX QUANTILE REGRESSION MODEL AND ITS ESTIMATION
Authors: Kong Efang , Xia Yingcun
Published: March 2012

Models with single-index structures are among the many existing popular semiparametric approaches for either the conditional mean or the conditional variance. This paper focuses on a single-index model for the conditional quantile. We propose an adaptive estimation procedure and an iterative algorithm which, under mild regularity conditions, is proved to converge with probability 1. The resulted estimator of the single-index parametric vector is root-n consistent, asymptotically normal, and based on simulation study, is more efficient than the average derivative method in Chaudhuri, Doksum, and Samarov (1997, Annals of Statistics 19, 760–777). The estimator of the link function converges at the usual rate for nonparametric estimation of a univariate function. As an empirical study, we apply the single-index quantile regression model to Boston housing data. By considering different levels of quantile, we explore how the covariates, of either social or environmental nature, could have different effects on individuals targeting the low, the median, and the high end of the housing market.
Payment for ecosystem services, sustained behavioural change, and adaptive management: peasant perspectives in the Colombian Andes
Authors: HAYES TANYA M.
Published: March 2012

Payment for ecosystem services (PES) has been widely promoted as an effective and efficient model for conservation; however, few studies have empirically examined how the market-based approach interacts with farmer's decision-making processes and their abilities to sustain new conservation practices. This paper examines the sustainability of a PES silvopastoral programme in Colombia from peasant farmers’ perspectives. Programme participants were asked questions regarding their perceived ability to continue with the silvopastoral practices, the influence of the economic benefits and contracts on behavioural change, and the programme's impacts on self-determination, innovation and social learning; factors considered critical for sustained resource management. While the participants expressed a need for the PES programme practices, less than half stated that they would continue with the silvopastoral measures and only 13% understood that part of their contractual commitment was to conserve forests. Ten per cent of the participants considered themselves the principal decision-maker in the farm-level changes and only one participant had altered the prescribed practices, despite a common perception that some techniques were not suitable for the region. The results suggest a need to re-examine the degree to which the PES model in fact encourages adaptive management practices and sustained land-use behaviours in peasant communities.
Varied success from the landscape-scale management of kiwi Apteryx spp. in five sanctuaries in New Zealand
Authors: ROBERTSON HUGH A. , de MONCHY PIM J. M.
Published: March 2012

In late 2000, five sanctuaries were established on the mainland of New Zealand for the express purpose of protecting populations of five kiwi Apteryx spp. taxa belonging to three species. Conservation management was undertaken at a landscape scale (10,000–20,000 ha) in each sanctuary to improve recruitment of kiwi. This was done by controlling introduced mammalian predators (especially stoats Mustela erminea), and/or by removing eggs and chicks from predation risk, and returning subadults when they were big enough to cope with stoats. Population modelling of the first five years of the sanctuary programme indicated that kiwi numbers in all five sanctuaries would increase as a result of the management. Calculated population increases varied from 0.6% per year at Okarito to 11.3% per year at Moehau, even though predator trapping was more intense at Okarito. The variation from site to site was explained by the widely different inherent productivity of the various kiwi taxa; widely different rates of adult mortality due to the presence or absence of dogs Canis familiaris and ferrets M. furo, the main predators of long-lived adult kiwi; and, local forest conditions affecting predator-prey cycles, and the density of stoats. As a result of this analysis, the management in four of the five sanctuaries has since been modified to try to achieve better overall gains for kiwi within the same operating budget.
Reading the Tea Leaves: Understanding Tea Party Caucus Membership in the US House of Representatives
Authors: Gervais Bryan T. , Morris Irwin L.
Published: March 2012

In the summer of 2010, 52 Republican members of the US House of Representatives joined the newly formed Tea Party Caucus, bringing the first institutional voice to the Tea Party movement. To understand both thepolicyorientations of the organized Tea Party (in its caucus manifestation) and the institutional strength of the caucus's membership, we assess the extent to which caucus members are distinctive from their fellow Republicans in the US House of Representatives. Our results suggest that membership in the caucus is primarily driven by ideology and economics. Specifically, we find that Tea Party Caucus members are Republicans who are ideologically oriented toward limited government and lower taxes and who hail from particularly prosperous congressional districts. We find no evidence that Tea Party Caucus members serve safer districts or have greater seniority or institutional stature than their Republican colleagues who are not members of the caucus. These findings, we believe, speak not only to the nature and orientations of the Tea Party Caucus, but to the wider Tea Party movement itself.
US Media Coverage of the Cancún Climate Change Conference
Authors: Boykoff Jules
Published: March 2012

Much was at stake at the 2010 United Nations climate change conference in Cancún, Mexico. The United Nations Framework Convention on Climate Change was being challenged by the world's two largest greenhouse gas emitters, China and the United States, after these countries reached a tenuous backroom deal one year earlier in Copenhagen. Meanwhile, scientific studies were warning of serious and severe climate change. This article analyzes newspaper articles and television segments from the US media that appeared during the timeframe of the Cancún conference, focusing on two key facets of coverage that continue to be important as negotiations proceed: the economic impacts and opportunities that climate change creates and the role that China plays in negotiations. I also examine which sources were allowed through the news gates and which ones were marginalized. I find that the US media discussed economic opportunities more frequently than economic impacts and that the media treated China in an even-handed way. Established political actors dominated coverage, followed by representatives of nongovernmental organizations and the business community. Meanwhile, grassroots activists and indigenous voices were marginalized.
An Interesting Bias: Lessons from an Academic's Year as a Reporter
Authors: Niven David
Published: March 2012

Most rigorous studies conclude that there is no consistent partisan or ideological bias in the mainstream American news media. This suggests a natural but little-asked question: Why isn't there more bias in the media? A year spent working as a journalist suggests a possible answer: Advancing a political perspective does not help secure a place on the front page. Instead, the core incentive for a journalist is to be interesting. Interesting work that reveals the essence of a situation garners a more prominent spot in the newspaper and all its associated benefits. Because “interesting” sources are found on both the left and the right, among Republicans and Democrats, balance does not require a Solomonic commitment to fairness. Rather, balance can be achieved merely as a by-product of the effort to be interesting.
The Making of the Pundit, 2010: When Strong Ties Trump Weak Ones
Authors: Musgrave Paul
Published: March 2012

Many observers have argued that social media such as Facebook and Twitter will help opposition activists coordinate and overcome authoritarian regimes; others believe that such tools will have little impact. Evidence from the “Arab Spring” is inconclusive, with advocates for each position finding support in the events in Tunisia, Egypt, and elsewhere. When does social media help political movements succeed? Motivated by an experience serving as a “campaign manager” for a colleague's bid to become the Washington Post's “Next Great Pundit,” I argue that relying on Internet-based social networking tools (such as Facebook and Twitter) may lead campaigns to perform more poorly when the regime is able to change the election's rules in mid-campaign. Consequently, researchers observing only the messages broadcast by social media will miss the true coordination taking place, which happens through channels unobservable to the regime. Examples from Middle Eastern politics suggest that real-world political activists recognize these distinctions and adjust their messaging accordingly.
Learning through Writing: Teaching Critical Thinking Skills in Writing Assignments
Authors: Çavdar Gamze , Doe Sue
Published: March 2012

Traditional writing assignments often fall short in addressing problems in college students' writing as too often these assignments fail to help students develop critical thinking skills and comprehension of course content. This article reports the use of a two-part (staged) writing assignment with postscript as a strategy for improving critical thinking in a lower-division political science course. We argue that through well-designed writing assignments, instructors can encourage students to reconsider concepts, critically evaluate assumptions, and undertake substantive revisions of their writing.
Political Influence and TARP: An Analysis of Treasury's Disposition of CPP Warrants
Authors: Puente Lucas
Published: March 2012

I investigate one mechanism through which financial institutions could have used political influence to receive preferential treatment in the US Department of the Treasury-administered “bailout.” I find that neither proxies of political influence nor other political variables, such as public interest in specific deals, can explain variance in the sale price of warrants (a type of financial asset) Treasury acquired through TARP's Capital Purchase Program. Moreover, I find that the more politically active the firm is, the more likely Treasury is to auction its warrants (thereby receiving fair market value). This conclusion is not consistent with recent studies investigating the role of such variables in the initial administration of TARP and can be interpreted as good news for American taxpayers.
Data, Methods, and Theoretical Implications
Authors: Hannagan Rebecca J. , Schneider Monica C. , Greenlee Jill S.
Published: March 2012

Within the subfields of political psychology and the study of gender, the introduction of new data collection efforts, methodologies, and theoretical approaches are transforming our understandings of these two fields and the places at which they intersect. In this article we present an overview of the research that was presented at a National Science Foundation (NSF) (#SES-1014854) funded conference “New Research on Gender in Political Psychology” at Rutgers University in March 2011. This scholarship represents the expanding questions and approaches that enhance our understanding of gender within political psychology. As a result, we suggest that further innovation is needed with regard to theory and methods to understand better how gender shapes the political attitudes and actions of individuals. Our discussion here covers the use of data, interdisciplinary methods, and intersectionality to study gender. We conclude with thoughts about the theoretical implications of this recent scholarship and the future of political science research on gender.
Annual Report of the Editors of the American Political Science Review, 2010–2011
Authors: Rogowski Ronald
Published: March 2012

We report on the journal's operations during the year from July 1, 2010, to June 30, 2011. We once again express our thanks to the APSA: Presidents Brady and Pateman, the staff (especially Michael Brintnall and Polly Karpowicz), Council, and Publications Committee. (While we have enjoyed ready access to previous presidents, it has been a new experience to have an APSA president right down the hall from the lead editor.) Members of our Editorial Board, this year as last, have given us wise counsel on more than a few submissions. Joseph Riser, our senior editor, has continued his seemingly tireless and unflappable service; and our editorial assistants, Joslyn Barnhart, Darin Dewitt, and Beltrán Undurraga, have pulled together in harness as have few previous teams, keeping our technical processing rapid and our backlog almost always at zero. As rotation on the panel of co-editors continues, we express our profound gratitude to departing editor Jeff Lewis, who exhibited a new level of masochism by becoming UCLA department chair, but who also agreed to finish (and since has finished) all of his pending assignments and to be available for consultations on an “as needed” basis. We also thank, once again, the authors who submitted their papers for consideration, the referees who reviewed them, and the patience, dedication, and forbearance that all demonstrated.
Action Reflections: A Client-Centered Technique to Bridge the WHY–HOW Transition in Motivational Interviewing
Authors: Resnicow Ken , McMaster Fiona , Rollnick Stephen
Published: March 2012

Background: When using Motivational Interviewing (MI), once resistance or ambivalence are resolved and motivation is solidified, many practitioners struggle with how best to transition the discussion toward action planning, while still retaining the spirit and style of client centeredness, i.e., moving from the WHY phase to the HOW phase of counseling in a style that is MI-consistent. For many, there is a perception that the counseling style, skills, and strategies used to build motivation are distinct from those used in the action planning phase. The WHY to HOW transition does not, however, necessitate abandoning a client-centered style for a more overtly educational or directive style. Goal setting, action planning, provision of advice, and relapse prevention can be implemented from an autonomy supportive, MI consistent framework. Method: To this end, this article will present a new class of reflection, which we have termed “action reflections”, that can be used to help bridge the WHY-HOW gap. Action reflections (AR) allow the clinician to maintain a tone and orientation that are consistent with MI, i.e. autonomy support; guiding versus directing, during the action phase of counseling. They differ from reflecting change talk as they focus not on the WHY of change, but the HOW, WHEN, or WHERE. Action Reflections (ARs) also differ from the more common type of reflections such as those that focus on client feelings, rolling with resistance, or acknowledging ambivalence as ARs usually contain a potential concrete step that the client has directly or obliquely mentioned. Like any type of reflection, ARs represent the clinician's best guess for what the client has said or, more apropos here, where the conversation might be heading. Conclusion: This article describes the various types of ARs and provides examples of each to help clinicians incorporate them into their behavior change counseling.
Maternal–child overweight/obesity and undernutrition in Kenya: a geographic analysis
Authors: Pawloski Lisa R , Curtin Kevin M , Gewa Constance , Attaway David
Published: March 2012

Objective

The purpose of the study was to examine geographic relationships of nutritional status (BMI), including underweight, overweight and obesity, among Kenyan mothers and children.

Design

Spatial relationships were examined concerning BMI of the mothers and BMI-for-age percentiles of their children. These included spatial statistical measures of the clustering of segments of the population, in addition to inspection of co-location of significant clusters.

Setting

Rural and urban areas of Kenya, including the cities of Nairobi and Mombasa, and the Kisumu region.

Subjects

Mother–child pairs from Demographic and Health Survey data including 1541 observations in 2003 and 1592 observations in 2009. These mother–child pairs were organized into 399 locational clusters.

Results

There is extremely strong evidence that high BMI values exhibit strong spatial clustering. There were co-locations of overweight mothers and overweight children only in the Nairobi region, while both underweight mothers and children tended to cluster in rural areas. In Mombasa clusters of overweight mothers were associated with normal-weight children, while in the Kisumu region clusters of overweight children were associated with normal-weight mothers.

Conclusions

These findings show there is geographic variability as well as some defined patterns concerning the distribution of malnutrition among mothers and children in Kenya, and suggest the need for further geographic analyses concerning the potential factors which influence nutritional status in this population. In addition, the methods used in this research may be easily applied to other Demographic and Health Survey data in order to begin to understand the geographic determinants of health in low-income countries.
Parents’ misperceptions of social norms for pre-school children's snacking behaviour
Authors: Lally Phillippa , Cooke Lucy , McGowan Laura , Croker Helen , Bartle Naomi , Wardle Jane
Published: March 2012

Objective

Misperception of social norms may result in normalising unhealthy behaviours. The present study tested the hypothesis that parents overestimate both the frequency of unhealthy snacking in pre-school children other than their own (descriptive norms) and its acceptability to other parents (injunctive norms).

Design

A cross-sectional, self-report community survey. Questions assessed the frequency with which respondents’ own child ate unhealthy snacks and their beliefs about the appropriate frequency for children to snack. Perceived descriptive norms were assessed by asking parents to estimate how often other 2–4 year-old children in their area ate snacks. Perceived injunctive norms were assessed by asking them about other parents’ beliefs regarding the appropriate frequency for snacks. Misperceptions were assessed from (i) the difference between the prevalence of daily snacking and parents’ perceived prevalence and (ii) the difference between acceptability of daily snacking and parents’ beliefs about its acceptability to others.

Setting

Pre-schools and children's centres in one borough of London, UK.

Subjects

Parents (n 432) of children age 2–4 years.

Results

On average, parents believed that more than half of ‘other’ children had snacks at least daily, while prevalence data indicated this occurred in only 10 % of families. The same discrepancy was observed for perceived injunctive norms: parents overestimated other parents’ acceptance of frequent snacking, with two-thirds of parents having a self v. others discrepancy.

Conclusions

Misperceptions were identified for descriptive and injunctive norms for children's snacking. Accurate information could create less permissive norms and motivate parents to limit their child's intake of unhealthy snacks.
Temporal trends and anaemia-associated factors in 6- to 59-month-old children in Northeast Brazil
Authors: Leal Luciana Pedrosa , Batista Filho Malaquias , de Lira Pedro Israel Cabral , Figueiroa José Natal , Osório Mônica Maria
Published: March 2012

Objective

To analyse the trends and factors associated with anaemia in 6- to 59-month-old children in Northeast Brazil.

Design

Cross-sectional study assessed information from the second and third Pernambuco State Health and Nutrition Surveys carried out in 1997 and 2006. A multiple regression analysis was performed from a conceptual model addressing biological and socio-economic factors, housing and sanitation conditions, maternal factors, health care and nutrition, consumption, morbidity and nutritional status. Poisson's regression with robust variance was used.

Setting

Pernambuco, Brazil.

Subjects

A total of 777 and 993 children, respectively, in the second and third Pernambuco State Health and Nutrition Surveys.

Results

The prevalence of anaemia (Hb < 11 g/dl) decreased by 19·3 % (40·9 % down to 33·0 %) between surveys. Maternal education level (less than 8 years in school), households ranked in the lowest environmental index tertile and children between 6 and 23 months of age were the variables common to the final models in the surveys of 1997 and 2006. Elements like living in rural areas, household income less than two minimum official wages and low birth weight were still present in the final model of the 1997 survey. Households ranked in the lowest economic index tertile were associated with anaemia in the model of the 2006 survey.

Conclusions

The study results are quite encouraging from the perspective of reducing the prevalence of anaemia. Maternal education level, environmental conditions and child age were determinant factors in both surveys, and economic factors were determinant in 2006.
IS AN INFINITE TEMPORAL REGRESS OF EVENTS POSSIBLE?
Authors: Loke Andrew Ter Ern
Published: March 2012

Issues concerning the ultimate origins of the universe have generated huge public interest recently. It began with the publication of The Grand Design by Stephen Hawking and Leonard Mlodinow, in which the authors claim that, because there is a law like gravity, the universe can and will create itself from nothing, and thus there is no role for God. This has prompted heated responses from scientists, philosophers, and religious leaders in the media, many of them asking, in effect, ‘where that law came from’. Subsequently, Roger Penrose released his new book Cycles of Time, arguing that what came before the Big Bang was the end of another universe, prompting the question whether there is an infinite temporal regress of universes or not. These discussions make it very timely to examine afresh whether an infinite temporal regress of events is possible.
STUDY ABROAD'S CONTRIBUTION TO CRITICAL THINKING AND WORLD CITIZENSHIP
Authors: Nguyen A. Minh
Published: March 2012

This paper articulates and defends two theses due to Richard Paul and Linda Elder. First, creative thought and critical thought cannot be separated. Second, the intellectual traits constitutive of critical thinking are interdependent. The twin theses combined with certain impact studies show that study abroad enhances both creativity and criticality. The primary value of such gains resides in their potential to realize not only the Socratic ideal of rationality but also the Diogenean ideal of cosmopolitanism. The former consists in the cultivation of fair-minded, creative, and critical individuals and societies, whereas the latter consists in the cultivation of citizens of the world and the single community to which they belong. Since study abroad can lead to intellectual growth in participants, this paper recommends certain policies and practices to help ensure the desired gain.
THE SOUL IN OLD AND NEW INTERPRETATION
Authors: Wells George A.
Published: March 2012

In his immensely popular L’Irréligion de L'Avenir (The Non-Religion of the Future) J.M. Guyau showed that the soul has been invoked to account (among other things) for the difference between the living and the dead and for dreams. The breath, he said, was the most tangible thing, other than the blood, with which life could be definitely associated. It could even be heard leaving the body at the last gasp. It seems to be immaterial and invisible, so that it is not surprising that in many languages words for soul or spirit are derived from words meaning the breath or the wind. As for dreams, Guyau pointed out that the dreamer experiences adventures, yet is assured by his companions that he did not leave the room or the tent at all during the night, and that this could be explained by supposing that there is a soul that can leave the body, roam the country, and then return to its normal corporeal abode. In dreams one not only goes on adventures, but also meets friends and talks with them, yet thereafter they know nothing of the meeting. Some semblance of them had therefore been separated from their bodies without their knowledge. Sometimes these simulacra belong to the dead and must therefore represent some portion of those persons that survived death.
The influence of ozone precursor emissions from four world regions on tropospheric composition and radiative climate forcing
Authors: Fry Meridith M. , Naik Vaishali , West J. Jason , Schwarzkopf M. Daniel , Fiore Arlene M. , Collins William J. , Dentener Frank J. , Shindell Drew T. , Atherton Cyndi , Bergmann Daniel , Duncan Bryan N. , Hess Peter , MacKenzie Ian A. , Marmer Elina , Schultz Martin G. , Szopa Sophie , Wild Oliver , Zeng Guang
Published: March 2012

Ozone (O3) precursor emissions influence regional and global climate and air quality through changes in tropospheric O3 and oxidants, which also influence methane (CH4) and sulfate aerosols (SO42−). We examine changes in the tropospheric composition of O3, CH4, SO42− and global net radiative forcing (RF) for 20% reductions in global CH4 burden and in anthropogenic O3 precursor emissions (NOx, NMVOC, and CO) from four regions (East Asia, Europe and Northern Africa, North America, and South Asia) using the Task Force on Hemispheric Transport of Air Pollution Source‐Receptor global chemical transport model (CTM) simulations, assessing uncertainty (mean ± 1 standard deviation) across multiple CTMs. We evaluate steady state O3responses, including long‐term feedbacks via CH4. With a radiative transfer model that includes greenhouse gases and the aerosol direct effect, we find that regional NOx reductions produce global, annually averaged positive net RFs (0.2 ± 0.6 to 1.7 ± 2 mWm−2/Tg N yr−1), with some variation among models. Negative net RFs result from reductions in global CH4 (−162.6 ± 2 mWm−2 for a change from 1760 to 1408 ppbv CH4) and regional NMVOC (−0.4 ± 0.2 to −0.7 ± 0.2 mWm−2/Tg C yr−1) and CO emissions (−0.13 ± 0.02 to −0.15 ± 0.02 mWm−2/Tg CO yr−1). Including the effect of O3 on CO2 uptake by vegetation likely makes these net RFs more negative by −1.9 to −5.2 mWm−2/Tg N yr−1, −0.2 to −0.7 mWm−2/Tg C yr−1, and −0.02 to −0.05 mWm−2/Tg CO yr−1. Net RF impacts reflect the distribution of concentration changes, where RF is affected locally by changes in SO42−, regionally to hemispherically by O3, and globally by CH4. Global annual average SO42− responses to oxidant changes range from 0.4 ± 2.6 to −1.9 ± 1.3 Gg for NOxreductions, 0.1 ± 1.2 to −0.9 ± 0.8 Gg for NMVOC reductions, and −0.09 ± 0.5 to −0.9 ± 0.8 Gg for CO reductions, suggesting additional research is needed. The 100‐year global warming potentials (GWP100) are calculated for the global CH4 reduction (20.9 ± 3.7 without stratospheric O3 or water vapor, 24.2 ± 4.2 including those components), and for the regional NOx, NMVOC, and CO reductions (−18.7 ± 25.9 to −1.9 ± 8.7 for NOx, 4.8 ± 1.7 to 8.3 ± 1.9 for NMVOC, and 1.5 ± 0.4 to 1.7 ± 0.5 for CO). Variation in GWP100 for NOx, NMVOC, and CO suggests that regionally specific GWPs may be necessary and could support the inclusion of O3 precursors in future policies that address air quality and climate change simultaneously. Both global net RF and GWP100 are more sensitive to NOx and NMVOC reductions from South Asia than the other three regions.
The characteristic variability and connection to the underlying synoptic activity of the Amundsen‐Bellingshausen Seas Low
Authors: Fogt Ryan L. , Wovrosh Alex J. , Langen Ryan A. , Simmonds Ian
Published: March 2012

Recent studies have noted an asymmetrical climate change across Antarctica, with significant warming in West Antarctica and the Antarctica Peninsula, and primarily insignificant trends in East Antarctica. Due to its proximity, variations in the position and intensity of the Amundsen‐Bellingshausen Seas Low (ABSL) are a suspected atmospheric mechanism. Here, we investigate the ABSL to understand its characteristic variability and underlying synoptic‐scale influences, based on three reanalysis data sets. The ABSL is defined as the minimum monthly pressure in the 45°–75°S, 180°–60°W domain. Using this criterion, a significant north‐south and east‐west progression is noted in the climatological (1979–2001 average) ABSL, which is strongly tied to the location of the maximum cyclone system density and minimum cyclone central pressures. More than 550 cyclones a year were identified in the vicinity of the ABSL; during spring, significant trends in their central pressures are noted in the Ross Sea. The implied changes in temperature advection by these stronger systems are consistent with the warming in West Antarctica. The strongest cyclone events (i.e., the ten with the deepest central pressures) also demonstrate a connection to the climatological ABSL, albeit weaker. Moreover, these strong cyclone events are significantly linked to the Southern Annular Mode (SAM), particularly in their annual frequency and location/steering in the summer. This shows that large‐scale forcing, such as from the SAM, may influence the strongest cyclones in the region and could allow for the prediction of such events.
Upscaling unsaturated flow in binary porous media with air entry pressure effects
Authors: Szymkiewicz Adam , Helmig Rainer , Neuweiler Insa
Published: March 2012

We consider flow in a porous medium containing coarse‐textured inclusions with a low value of air entry pressure, embedded in a fine‐textured background material having high entry pressure. During imbibition some air remains trapped in the inclusions, while during drainage the inclusions become drained only after the capillary entry pressure exceeds the pressure of the background material. These effects can only be reproduced by a two‐phase flow model, and not by the Richards' equation. However, if an upscaled form of the Richards' equation with appropriately modified capillary and permeability functions is used, the results are in a reasonable agreement with the two‐phase flow model.
Exploring changes in the spatial distribution of stream baseflow generation during a seasonal recession
Authors: Payn R. A. , Gooseff M. N. , McGlynn B. L. , Bencala K. E. , Wondzell S. M.
Published: March 2012

Relating watershed structure to streamflow generation is a primary focus of hydrology. However, comparisons of longitudinal variability in stream discharge with adjacent valley structure have been rare, resulting in poor understanding of the distribution of the hydrologic mechanisms that cause variability in streamflow generation along valleys. This study explores detailed surveys of stream base flow across a gauged, 23 km2 mountain watershed. Research objectives were (1) to relate spatial variability in base flow to fundamental elements of watershed structure, primarily topographic contributing area, and (2) to assess temporal changes in the spatial patterns of those relationships during a seasonal base flow recession. We analyzed spatiotemporal variability in base flow using (1) summer hydrographs at the study watershed outlet and 5 subwatershed outlets and (2) longitudinal series of discharge measurements every ∼100 m along the streams of the 3 largest subwatersheds (1200 to 2600 m in valley length), repeated 2 to 3 times during base flow recession. Reaches within valley segments of 300 to 1200 m in length tended to demonstrate similar streamflow generation characteristics. Locations of transitions between these segments were consistent throughout the recession, and tended to be collocated with abrupt longitudinal transitions in valley slope or hillslope‐riparian characteristics. Both within and among subwatersheds, correlation between the spatial distributions of streamflow and topographic contributing area decreased during the recession, suggesting a general decrease in the influence of topography on stream base flow contributions. As topographic controls on base flow evidently decreased, multiple aspects of subsurface structure were likely to have gained influence.
A general memory function for modeling mass transfer in groundwater transport
Authors: Cvetkovic Vladimir
Published: March 2012

A power‐law extension of the gamma distribution is proposed as a general memory function for capturing rate limitations of retention in groundwater transport. Using moments, we show how the new memory function can be reduced to most other forms available in the literature, exactly or approximately. The proposed formulation is suitable for field scale or laboratory scale transport modeling. Rate limitation effects are illustrated for solute transport by considering the fractional mass release over a given transport scale. The equilibrium and no‐retention cases set bounds for contaminant attenuation, between which the impact of rate limitations is clearly exposed.
Satellite geodetic imaging reveals internal deformation of western Tibet
Authors: Wang H. , Wright T. J.
Published: March 2012

It is often assumed that the majority of the interseismic strain accumulates around the major mapped geological block boundaries. However, numerous recent earthquakes in the continents have occurred on faults that were previously unidentified. Existing deformation data from Tibet are insufficiently dense to map the distribution of interseismic strain. Here we combine 265 interferograms formed from 166 radar images with GPS data to constrain a high‐resolution velocity field covering ∼200,000 km2 of western Tibet. We confirm that the slip rate of the Karakoram Fault is low (<6 mm/yr), but show that areas of focused strain do not coincide with the major fault structures. Some of this strain is due to postseismic relaxation after a Mw 6.8 earthquake that occurred in 1996 on a structure that is difficult to identify in satellite imagery. Models of seismic hazard that rely on imperfect knowledge of the boundaries of crustal blocks can therefore underestimate hazard from unknown faults.
The density and porosity of lunar rocks
Authors: Kiefer Walter S. , Macke Robert J. , Britt Daniel T. , Irving Anthony J. , Consolmagno Guy J.
Published: March 2012

Accurate lunar rock densities are necessary for constructing gravity models of the Moon's crust and lithosphere. Most Apollo‐era density measurements have errors of 2–5% or more and few include porosity measurements. We report new density and porosity measurements using the bead method and helium pycnometry for 6 Apollo samples and 7 lunar meteorites, with typical grain density uncertainties of 10–30 kg m−3 (0.3–0.9%) and porosity uncertainties of 1–3%. Comparison between igneous grain densities and normative mineral densities show that these uncertainties are realistic and that the helium fully penetrates the pore space. Basalt grain densities are a strong function of composition, varying over at least 3270 kg m−3 (high aluminum basalt) to 3460 kg m−3 (high titanium basalt). Feldspathic highland crust has a bulk density of 2200–2600 kg m−3 and porosity of 10–20%. Impact basin ejecta has a bulk density of 2350–2600 kg m−3 and porosity of ∼20%.
Hypoxia-Inducible Factor Prolyl Hydroxylase Inhibition: Robust New Target or Another Big Bust for Stroke Therapeutics?
Authors: Karuppagounder Saravanan S , Ratan Rajiv R
Published: March 2012

A major challenge in developing stroke therapeutics that augment adaptive pathways to stress has been to identify targets that can activate compensatory programs without inducing or adding to the stress of injury. In this regard, hypoxia-inducible factor prolyl hydroxylases (HIF PHDs) are central gatekeepers of posttranscriptional and transcriptional adaptation to hypoxia, oxidative stress, and excitotoxicity. Indeed, some of the known salutary effects of putative ‘antioxidant’ iron chelators in ischemic and hemorrhagic stroke may derive from their abilities to inhibit this family of iron, 2-oxoglutarate, and oxygen-dependent enzymes. Evidence from a number of laboratories supports the notion that HIF PHD inhibition can improve histological and functional outcomes in ischemic and hemorrhagic stroke models. In this review, we discuss this evidence and highlight important gaps in our understanding that render HIF PHD inhibition a promising but not yet preclinically validated target for protection and repair after stroke.
Concomitant dendrometer and leaf patch pressure probe measurements reveal the effect of microclimate and soil moisture on diurnal stem water and leaf turgor variations in young oak trees
Authors: Ehrenberger Wilhelm , Rüger Simon , Fitzke Ronald , Vollenweider Pierre , Günthardt-Goerg Madeleine , Kuster Thomas , Zimmermann Ulrich , Arend Matthias
Published: March 2012

Tree water relations and their dependence on microclimate and soil moisture were studied over several months in young oaks (Quercus robur L.) subjected in large lysimeter-based open top chambers to environments with a controlled soil water supply. Automated single point dendrometers and the recently developed leaf patch clamp pressure (LPCP) probe were used for monitoring water-related stem radius variations (ΔW) and turgor-dependent leaf patch pressures (Pp). Both parameters showed distinct diurnal patterns with sharp negative and positive peaking of ΔW and Pp, respectively, after solar noon and recovery to initial levels in the evening. During the day, varying solar radiation was responsible for short time fluctuations of Pp in the range of minutes to hours reflecting feedback regulation of leaf turgor by sunlight driven stomatal movements. At longer timescales, i.e. days to months, atmospheric vapour pressure deficit (VPD) and soil water content (SWC) were the main determinants of ΔW and Pp. Daily minimum and maximum values of ΔW and Pp decreased and increased, respectively, with increasing VPD or decreasing SWC and recovery of ΔW and Pp in the evening was impeded by low SWC. In well-watered oaks, daily positive peaking of Pp preceded daily negative peaking of ΔW; these time lags gradually increased with increasing soil drought, suggesting hydraulic uncoupling of stem and leaves.
The impact of winter flooding with saline water on foliar carbon uptake and the volatile fraction of leaves and fruits of lemon (Citrus×limon) trees
Authors: Velikova Violeta , La Mantia Tommaso , Lauteri Marco , Michelozzi Marco , Nogues Isabel , Loreto Francesco
Published: March 2012

We investigated the consequences of recurrent winter flooding with saline water on a lemon (Citrus × limon (L.) Burm.f.) orchard, focussing on photosynthesis limitations and emission of secondary metabolites (isoprenoids) from leaves and fruits. Measurements were carried out immediately after flooding (December), at the end of winter (April) and after a dry summer in which plants were irrigated with optimal quality water (September). Photosynthesis was negatively affected by flooding. The effect was still visible at the end of winter, whereas the photosynthetic rate was fully recovered after summer, indicating an unexpected resilience capacity of flooded plants. Photosynthesis inhibition by flooding was not due to diffusive limitations to CO2 entry into the leaf, as indicated by measurements of stomatal conductance and intercellular CO2 concentration. Biochemical and photochemical limitations seemed to play a more important role in limiting the photosynthesis of flooded plants. In young leaves, characterised by high rates of mitochondrial respiration, respiratory rates were enhanced by flooding. Flooding transiently caused large and rapid emission of several volatile isoprenoids. Emission of limonene, the most abundant compound, was stimulated in the leaves, and in young and mature fruits. Flooding changed the blend of emitted isoprenoids, but only few changes were observed in the stored isoprenoids pool.
Fetal growth restriction in hypothyroidism is associated with changes in proliferative activity, apoptosis and vascularisation of the placenta
Authors: Silva Juneo F. , Vidigal Paula N. , Galvão Daniele D. , Boeloni Jankerle N. , Nunes Philipe Pimenta , Ocarino Natália M. , Nascimento Ernane F. , Serakides Rogéria
Published: March 2012

The objective of this study was to evaluate fetal weight, histomorphometric changes and proliferative activity, apoptosis and angiogenesis of the placenta in rats with hypothyroidism. Thirty-six adult female rats were divided into two groups with 18 animals each: control and hypothyroidism. Hypothyroidism was induced by daily administration of propylthiouracil (1 mg/animal). The administration began five days before becoming pregnant and the animals were sacrificed at 14 or 19 days of gestation. The control group received a placebo. The number and weight of fetuses and the rate of fetal death was determined, as well as the morphometric characteristics, the immunohistochemical expression of cell division control protein 47 (CDC)-47 and vascular endothelial growth factor (VEGF) and the number of apoptotic cells in the placental disk. The data were analysed by Mann–Whitney U test. Hypothyroidism reduced the weight of fetuses and of the uterus and placenta (P < 0.05), altered the thickness of the placental labyrinth and spongiotrophoblast (P < 0.05), increased the population of glycogen cells in the spongiotrophoblast (P < 0.05), interfered with the vascular development of the placental labyrinth and decreased VEGF expression (P < 0.05), reduced the expression of CDC-47 and cellularity and increased the apoptotic rate in the placental disk (P < 0.05). We conclude that hypothyroidism affects fetal weight by altering the proliferative activity, apoptosis and vascularisation of the placenta.
Rescue of neuronal migration deficits in a mouse model of fetal Minamata disease by increasing neuronal Ca2+spike frequency
Authors: Fahrion Jennifer K. , Komuro Yutaro , Li Ying , Ohno Nobuhiko , Littner Yoav , Raoult Emilie , Galas Ludovic , Vaudry David , Komuro Hitoshi
Published: March 2012

In the brains of patients with fetal Minamata disease (FMD), which is caused by exposure to methylmercury (MeHg) during development, many neurons are hypoplastic, ectopic, and disoriented, indicating disrupted migration, maturation, and growth. MeHg affects a myriad of signaling molecules, but little is known about which signals are primary targets for MeHg-induced deficits in neuronal development. In this study, using a mouse model of FMD, we examined how MeHg affects the migration of cerebellar granule cells during early postnatal development. The cerebellum is one of the most susceptible brain regions to MeHg exposure, and profound loss of cerebellar granule cells is detected in the brains of patients with FMD. We show that MeHg inhibits granule cell migration by reducing the frequency of somal Ca2+spikes through alterations in Ca2+, cAMP, and insulin-like growth factor 1 (IGF1) signaling. First, MeHg slows the speed of granule cell migration in a dose-dependent manner, independent of the mode of migration. Second, MeHg reduces the frequency of spontaneous Ca2+spikes in granule cell somata in a dose-dependent manner. Third, a unique in vivo live-imaging system for cell migration reveals that reducing the inhibitory effects of MeHg on somal Ca2+spike frequency by stimulating internal Ca2+release and Ca2+influxes, inhibiting cAMP activity, or activating IGF1 receptors ameliorates the inhibitory effects of MeHg on granule cell migration. These results suggest that alteration of Ca2+spike frequency and Ca2+, cAMP, and IGF1 signaling could be potential therapeutic targets for infants with MeHg intoxication.
Desiccation Tolerance in a Wild Population of the Invasive Oriental Weatherfish Misgurnus anguillicaudatus in Idaho, USA
Authors: Koetsier Peter , Urquhart Alexander N.
Published: March 2012

The oriental weatherfish Misgurnus anguillicaudatus is a nonindigenous, cryptic species for which the currently invaded range spans 13 states in the USA as well as six other countries. Anecdotal evidence suggests that because they are facultative air‐breathers, oriental weatherfish can survive in the terrestrial environment and may move across land to colonize new water bodies. Given the lack of empirical research on this subject, we conducted an experiment with oriental weatherfish to determine their longevity under increasingly dry conditions and their tolerance to desiccation. We introduced the fish (obtained from a wild population in Idaho) into a series of tanks and allowed some of the tanks to dry out. Over the course of the experiment, we measured substrate moisture content and temperature in each tank, and we periodically removed some fish to determine changes in mass and to check the status (alive or dead) and viability of the fish. Some individuals survived for over 81 d in desiccated conditions with soil moisture content less than 3%; these fish lost over 25% of their body weight. No mortalities occurred in the control group, which lost no more than 20% of their body weight despite being unfed for nearly 90 d. Our findings add to a growing list of traits indicating that the oriental weatherfish fits the profile of a highly successful invader and therefore should be a species of concern.
Effect of Dietary Vitamin E on Cortisol and Glucose Responses to Handling Stress in Juvenile Beluga Huso huso
Authors: Falahatkar B. , Amlashi A. Safarpour , Conte F.
Published: March 2012

An 8-week feeding experiment was conducted to investigate the effect of dietary vitamin E on the physiological response to handling stress in juvenile beluga Huso huso. Fish were fed six experimental diets supplemented with 0, 25, 50, 100, 200, or 400 mg Dl-all-rac-α-tocopherol acetate/kg diet. At the end of the experiment, the fish in each tank were subjected to acute handling and air exposure stress. Cortisol and glucose were measured as the primary hormonal and secondary metabolic responses to the stressors, both before and 3 h after application of the stressors. The growth parameters and feed utilization rates were significantly lower in fish fed the diet not supplemented with vitamin E than in fish fed diets supplemented with vitamin E. Cortisol concentration was not affected by dietary treatment but glucose concentration was. Fish fed vitamin E at 0, 25, 100, and 400 mg/kg diet had higher concentrations of glucose than those fed vitamin E at 50 and 200 mg/kg. However, fish fed diets with 50 and 200 mg/kg exhibited higher growth rates. These results indicate that dietary vitamin E has some effect on plasma glucose but no effect on plasma cortisol. In general, when the stressors were applied to belugas, the glucose and cortisol responses were relatively low. This may be due to higher resistance and lower physiological responses to these types of stressors by this species or by chondrosteans in general.

Received January 10, 2011; accepted August 4, 2011