bluuebunny/crossref_metadata_2025 huggingface dataset:
Are high school students living in lodgings at an increased risk for internalizing problems?
Authors: Wannebo Wenche , Wichstr⊘m Lars
Published: July 2009

This study aimed to investigate whether leaving home to live in lodgings during senior high school can be a risk factor for the development of internalizing problems. Utilizing two large‐scale prospective community studies of 2399 and 3906 Norwegian students (age range 15–19 years), respectively, the difference in internalizing symptoms between adolescents living in lodgings and adolescents living with their parents during senior high school was examined. Female students living in lodgings had higher scores on internalizing problems than female students living at home, whereas no differences were found for males. Living in lodgings did not predict later internalizing problems, and prior internalizing problems did not predict moving into lodgings. It is therefore suggested that the negative effect of living in lodgings on high school students' well‐being is temporary.
Abnormal Antenatal Sonogram: An Indicator of Disease Severity in Children with Posterior Urethral Valves
Authors: Harvie Sarah , McLeod Lynne , Acott Philip , Walsh Eilish , Abdolell Mohamed , Macken Marian B.
Published: July 2009

Purpose

To review the association of an abnormal prenatal sonogram with most recent serum creatinine in patients with proven posterior urethral valves (PUV).

Methods

Since 1992, all live-born patients between 1992–2004 with clinically proven PUV, with postnatally proven PUV, from 2 pediatric tertiary care centers, were reviewed for age at diagnosis, most recent serum creatinine, presence of chronic renal failure (CRF) (serum creatinine >2 standard deviations above normal for age), or end stage renal disease (dialysis or transplant). Available antenatal reports from the 2 centres and surrounding community hospitals were reviewed for gestational age (GA) at the time of ultrasound, volume of amniotic fluid, and urinary-tract abnormality.

Results

Thirty-four patients with proven PUV and prenatal sonograms were identified (1992–2004). Eighteen patients had abnormalities on their prenatal sonogram, with poor outcome in 5 (mean follow-up, 8 years [1–13 y]). No specific features were identified on prenatal sonogram. Sixteen patients had normal prenatal sonograms, with poor outcomes in 2 (mean follow-up, 8 years [3–13y]). There is an increased risk of an abnormal serum creatinine among those patients with an abnormal prenatal study, odds ratio (OR) 2.6 (95% confidence interval, 0.35–32).

Conclusions

PUV represents a spectrum of disease severity. A normal prenatal ultrasound does not preclude PUV. The majority of patients with a normal prenatal examination have good outcomes. The OR suggests that there may be increased risk for poor outcome in those with an abnormal prenatal examination. A multicenter study is necessary to obtain a larger sample size and more precise ORs.
Too much theory, not enough understanding⋆
Authors: Schmenner Roger W. , Van Wassenhove Luk , Ketokivi Mikko , Heyl Jeff , Lusch Robert F.
Published: July 2009

This essay and the following commentaries address the use of theory in operations management. While much is said about theory in the typical journal article, theory, as science defines it, is not at the center of much of our research. The discipline had fallen into some bad habits. This essay and its commentaries appeal for more attention to what theory can mean for our understanding of operations management.
Stable isotope and 14C study of biogenic calcrete in a termite mound, Western Cape, South Africa, and its palaeoenvironmental significance
Authors: Potts Alastair J. , Midgley Jeremy J. , Harris Chris
Published: July 2009

Late Quaternary terrestrial climate records from the semi-arid zone of the Western Cape of South Africa are rare. However, palaeoenvironmental information may be inferred from ancient termite mounds of the region. Calcrete lenses in these mounds have δ13C and δ18O values that show systematic changes with radiocarbon dates, which range from 33,629–36,709 to 21,676–23,256 cal yr BP. These dates confirm that these heuweltjies had been present in the landscape since the last glacial period. The decrease in δ13C and δ18O from 33,629–36,709 to 21,676–23,256 cal yr BP indicates that climate information is recorded by the calcretes. It is suggested that a progressive decline in air temperature and an increase in moisture availability, and a decline in abundance of C4 or CAM plants, occurred in the region during the time heuweltjie calcite precipitated.
Molluscs as Evidence for a Late Pleistocene and Early Holocene Humid Period in the Southern Coastal Desert of Peru (14.5°S)
Authors: Mächtle Bertil , Unkel Ingmar , Eitel Bernhard , Kromer Bernd , Schiegl Solveig
Published: July 2009

The southern Peruvian coastal desert around Palpa, southern Peru (14.5°S) is currently characterized by hyper-arid conditions. However, the presence of two species of molluscs (Scutalus, Pupoides) and desert-loess deposits indicates the past development of semi-desert and grassland ecosystems caused by a displacement of the eastern desert margin due to hydrological changes. Radiocarbon dating shows that the transition to a semi-arid climate in the southern Peruvian coastal desert took place during the Greenland interstadial 1, ∼ 13.5 cal ka BP. At the beginning of the Holocene, the mollusc fauna vanished due to increasing humidity and the development of grasslands. Dust particles were fixed by the grasses, as indicated by abundant Poaceae phytoliths, and desert loess was formed. The humid period we observe here is out of phase with the palaeoenvironmental records from the Titicaca region, which indicates dry conditions at that time. This paper offers a new idea for this contradiction: an orbitally driven meridional shift of the Bolivian high might have altered the moisture supply across the Andes.
The Organization by Nations at Constance
Authors: Loomis Louise R.
Published: July 2009

The Council of Constance, like any other serious event involving many people and lasting over a considerable period of time, can be studied from many points of view. It started out as a gathering for purely ecclesiastical purposes. But some twenty or thirty thousand persons from every class of society, except, perhaps, the lowest, cannot come and remain together for almost four years to discuss one set of difficult and complicated questions without, intentionally or unintentionally, raising many other questions, social, religious, philosophic, economic and political, and forming for the moment, as it were, a microcosm of the forces of the age. Most of the issues that agitated Europe five hundred years ago cropped up sooner or later at Constance, the cost of living, the obnoxiousness of robber barons and private warfare, the right and wrong of tyrannicide, the conflict between Germans and Poles in the East and between English and French in the West, to say nothing of the special issues with which the Council was expected to deal, the claims of three popes to be the only true successors of St. Peter, the perilous teachings of Wiclef and Hus and the worldliness and corruption of church administration.
The Churches as Moral Courts of the Frontier
Authors: Sweet William W.
Published: July 2009

We Americans have been inclined to over-idealize the frontier period of our history, and have been perhaps too ready to resent any implication of unwonted moral laxity among the pioneers. It is now universally known that the great majority of the people who colonized the Atlantic seaboard came from the lower stratum of European society, and only a comparatively few represented the best in education and culture. Throughout the entire colonial period, at least until the colonial Awakenings, the great mass of the lower classes were little influenced by organized religion, and only a very small proportion of the total population of the thirteen colonies were members of the colonial churches. At the end of the colonial period there were undoubtedly more unchurched people in North America, in proportion to the population, than were to be found in any other land in Christendom.
Remembering Things That Never Occurred: The Effects of To-Be-Forgotten Stereotypical Information
Authors: Araya Tadesse , Ekehammar Bo , Akrami Nazar
Published: July 2009

Abstract. Participants, 68 female and male nonpsychology university students, studied stereotypical and nonstereotypical words either with an initially activated social category (immigrant prime) or with no social category (neutral prime). They were then instructed to either forget or remember the studied words. This was followed by a recognition test. Based on the Deese-Roediger-McDermott (DRM) paradigm and stereotype-accessibility research, we anticipated that the participants in the immigrant, but not in the neutral, prime condition would falsely recognize more nonstudied stereotypic attributes under a forget than a remember instruction. The results supported our hypothesis. Implications of the outcome for eyewitness testimony, juridical decision-making, and stereotype maintenance are discussed.
Design-Effects in Prospective and Retrospective Memory for Actions
Authors: Jahn Petra , Engelkamp Johannes
Published: July 2009

There is ample evidence that memory for action phrases such as “open the bottle” is better in subject-performed tasks (SPTs), i.e., if the participants perform the actions, than in verbal tasks (VTs), if they only read the phrases or listen to them. It is less clear whether also the sole intention to perform the actions later, i.e., a prospective memory task (PT), improves memory compared with VTs. Inconsistent findings have been reported for within-subjects and between-subjects designs. The present study attempts to clarify the situation. In three experiments, better recall for SPTs than for PTs and for PTs than for VTs were observed if mixed lists were used. If pure lists were used, there was a PT effect but no SPT over PT advantage. The findings were discussed from the perspective of item-specific and relational information.
Intuition Beyond Recognition: When Less Familiar Events Are Liked More
Authors: Betsch Tilmann , Hoffmann Katja , Hoffrage Ulrich , Plessner Henning
Published: July 2009

In a laboratory experiment, we compare the relative impact of two possible determinants of intuitive evaluative judgments: ease of recognition and total value of prior encounters with a target. Participants encode daily return values of shares on the stock market while watching videotaped ads on the computer screen. This dual-task procedure ensures that participants subsequently lack relevant event memories and thus have to rely on their intuition when evaluating the targets. In the presentation, the share appearing least frequently produced the highest sum of returns. In contrast, the share appearing most frequently produced the lowest sum of returns. Evaluative judgments reveal a preference for the share with the highest sum of returns, although, as evident from recognition latencies, it was the one that was more difficult to recognize. The results provide evidence for the value-account model of implicit attitude formation ( Betsch, Plessner, Schwieren, & Gütig, 2001 ), which predicts that intuitive evaluative judgments reflect the total value of prior encounters.
Strategic Aspects of Numerosity Judgment: The Effect of Task Characteristics
Authors: Luwel Koen , Verschaffel Lieven , Onghena Patrick , De Corte Erik
Published: July 2009

In previous investigations we documented that people use several strategies to determine different numerosities of blocks that are presented in a square grid. One of these strategies is the clever subtraction strategy, wherein the number of empty squares in the grid is subtracted from the total number of squares in the grid. In the present study we investigated participants’ flexibility in strategy use when varying the shape of the grid. Analysis of the results in terms of the theoretical framework of Lemaire and Siegler (1995 ) regarding strategic change shows that this contextual variable affected the frequency, execution time, and accuracy of subjects’ use of the subtraction strategy. The usefulness of this framework for analyzing the nature of the adaptation to contextual variations is discussed. From a methodological point of view, this study documents the potential of Beem’s (1993 , 1999) segmented linear regression models for assessing subjects’ strategy use in cognitive tasks.
Audience-Congruent Biases in Eyewitness Memory and Judgment
Authors: Kopietz René , Echterhoff Gerald , Niemeier Sarah , Hellmann Jens H. , Memon Amina
Published: July 2009

In studies on biased eyewitness memory, the biasing information about the witnessed event is typically detailed and specific. We investigated the influence of global biasing information, such as a co-witness’ impression of a suspect. Student participants watched a video depicting a bar-brawl involving a male target person. After retelling the incident to a generic fellow student who presumably disliked (vs. liked) the target person, participants exhibited audience-congruent biases in memory and judgment: They remembered more negative information about the target, believed he was more responsible, and assigned him longer penalties. No such effects were found when participants were less motivated to create a shared view about the incident (with the audience being a student from a different study field).
Nine exceptional radiations plus high turnover explain species diversity in jawed vertebrates
Authors: Alfaro Michael E. , Santini Francesco , Brock Chad , Alamillo Hugo , Dornburg Alex , Rabosky Daniel L. , Carnevale Giorgio , Harmon Luke J.
Published: July 2009

The uneven distribution of species richness is a fundamental and unexplained pattern of vertebrate biodiversity. Although species richness in groups like mammals, birds, or teleost fishes is often attributed to accelerated cladogenesis, we lack a quantitative conceptual framework for identifying and comparing the exceptional changes of tempo in vertebrate evolutionary history. We develop MEDUSA, a stepwise approach based upon the Akaike information criterion for detecting multiple shifts in birth and death rates on an incompletely resolved phylogeny. We apply MEDUSA incompletely to a diversity tree summarizing both evolutionary relationships and species richness of 44 major clades of jawed vertebrates. We identify 9 major changes in the tempo of gnathostome diversification; the most significant of these lies at the base of a clade that includes most of the coral-reef associated fishes as well as cichlids and perches. Rate increases also underlie several well recognized tetrapod radiations, including most modern birds, lizards and snakes, ostariophysan fishes, and most eutherian mammals. In addition, we find that large sections of the vertebrate tree exhibit nearly equal rates of origination and extinction, providing some of the first evidence from molecular data for the importance of faunal turnover in shaping biodiversity. Together, these results reveal living vertebrate biodiversity to be the product of volatile turnover punctuated by 6 accelerations responsible for >85% of all species as well as 3 slowdowns that have produced “living fossils.” In addition, by revealing the timing of the exceptional pulses of vertebrate diversification as well as the clades that experience them, our diversity tree provides a framework for evaluating particular causal hypotheses of vertebrate radiations.
NFAT isoforms control activity-dependent muscle fiber type specification
Authors: Calabria Elisa , Ciciliot Stefano , Moretti Irene , Garcia Marta , Picard Anne , Dyar Kenneth A. , Pallafacchina Giorgia , Tothova Jana , Schiaffino Stefano , Murgia Marta
Published: July 2009

The intracellular signals that convert fast and slow motor neuron activity into muscle fiber type specific transcriptional programs have only been partially defined. The calcium/calmodulin-dependent phosphatase calcineurin (Cn) has been shown to mediate the transcriptional effects of motor neuron activity, but precisely how 4 distinct muscle fiber types are composed and maintained in response to activity is largely unknown. Here, we show that 4 nuclear factor of activated T cell (NFAT) family members act coordinately downstream of Cn in the specification of muscle fiber types. We analyzed the role of NFAT family members in vivo by transient transfection in skeletal muscle using a loss-of-function approach by RNAi. Our results show that, depending on the applied activity pattern, different combinations of NFAT family members translocate to the nucleus contributing to the transcription of fiber type specific genes. We provide evidence that the transcription of slow and fast myosin heavy chain (MyHC) genes uses different combinations of NFAT family members, ranging from MyHC-slow, which uses all 4 NFAT isoforms, to MyHC-2B, which only uses NFATc4. Our data contribute to the elucidation of the mechanisms whereby activity can modulate the phenotype and performance of skeletal muscle.
Rapid formin-mediated actin-filament elongation is essential for polarized plant cell growth
Authors: Vidali Luis , van Gisbergen Peter A. C. , Guérin Christophe , Franco Paula , Li Ming , Burkart Graham M. , Augustine Robert C. , Blanchoin Laurent , Bezanilla Magdalena
Published: July 2009

Formins are present in all eukaryotes and are essential for the creation of actin-based structures responsible for diverse cellular processes. Because multicellular organisms contain large formin gene families, establishing the physiological functions of formin isoforms has been difficult. Using RNAi, we analyzed the function of all 9 formin genes within the moss
Physcomitrella patens
. We show that plants lacking class II formins (For2) are severely stunted and composed of spherical cells with disrupted actin organization. In contrast, silencing of all other formins results in normal elongated cell morphology and actin organization. Consistent with a role in polarized growth, For2 are apically localized in growing cells. We show that an N-terminal phosphatase tensin (PTEN)-like domain mediates apical localization. The PTEN-like domain is followed by a conserved formin homology (FH)1-FH2 domain, known to promote actin polymerization. To determine whether apical localization of any FH1-FH2 domain mediates polarized growth, we performed domain swapping. We found that only the class II FH1-FH2, in combination with the PTEN-like domain, rescues polarized growth, because it cannot be replaced with a similar domain from a For1. We used in vitro polymerization assays to dissect the functional differences between these FH1-FH2 domains. We found that both the FH1 and the FH2 domains from For2 are required to mediate exceptionally rapid rates of actin filament elongation, much faster than any other known formin. Thus, our data demonstrate that rapid rates of actin elongation are critical for driving the formation of apical filamentous actin necessary for polarized growth.
Neural stem cells improve cognition via BDNF in a transgenic model of Alzheimer disease
Authors: Blurton-Jones Mathew , Kitazawa Masashi , Martinez-Coria Hilda , Castello Nicholas A. , Müller Franz-Josef , Loring Jeanne F. , Yamasaki Tritia R. , Poon Wayne W. , Green Kim N. , LaFerla Frank M.
Published: July 2009

Neural stem cell (NSC) transplantation represents an unexplored approach for treating neurodegenerative disorders associated with cognitive decline such as Alzheimer disease (AD). Here, we used aged triple transgenic mice (3xTg-AD) that express pathogenic forms of amyloid precursor protein, presenilin, and tau to investigate the effect of neural stem cell transplantation on AD-related neuropathology and cognitive dysfunction. Interestingly, despite widespread and established Aß plaque and neurofibrillary tangle pathology, hippocampal neural stem cell transplantation rescues the spatial learning and memory deficits in aged 3xTg-AD mice. Remarkably, cognitive function is improved without altering Aß or tau pathology. Instead, the mechanism underlying the improved cognition involves a robust enhancement of hippocampal synaptic density, mediated by brain-derived neurotrophic factor (BDNF). Gain-of-function studies show that recombinant BDNF mimics the beneficial effects of NSC transplantation. Furthermore, loss-of-function studies show that depletion of NSC-derived BDNF fails to improve cognition or restore hippocampal synaptic density. Taken together, our findings demonstrate that neural stem cells can ameliorate complex behavioral deficits associated with widespread Alzheimer disease pathology via BDNF.
Modulation of transcription antitermination in the
bgl
operon of Escherichia coli by the PTS
Authors: Raveh Hadas , Lopian Livnat , Nussbaum-Shochat Anat , Wright Andrew , Amster-Choder Orna
Published: July 2009

BglG, which regulates expression of the β-glucoside utilization (
bgl
) operon in
Escherichia coli
, represents a family of RNA-binding transcriptional antiterminators that positively regulate transcription of sugar utilization genes in Gram-negative and Gram-positive organisms. BglG is negatively regulated by the β-glucoside phosphotransferase, BglF, by means of phosphorylation and physical association, and it is positively regulated by the general phosphoenolpyruvate phosphotransferase system (PTS) proteins, enzyme I (EI) and HPr. We studied the positive regulation of BglG both in vitro and in vivo. Here, we show that although EI and HPr are essential for BglG activity, this mode of activation does not require phosphorylation of BglG by HPr, as opposed to the phosphorylation-mediated activation of many BglG-like antiterminators in Gram-positive organisms. The effect of EI and HPr on BglG is not mediated by BglF. Nevertheless, the release of BglG from BglF, which is stimulated by the extracellular sugar in a sugar uptake-independent manner, is a prerequisite for BglG activation. Taken together, the results indicate that activation of BglG is a 2-stage process: a sugar-stimulated release from the membrane-bound sugar sensor followed by a phosphorylation-independent stimulatory effect exerted by the general PTS proteins.
An organometallic route to long helicenes
Authors: Sehnal Petr , Stará Irena G. , Šaman David , Tichý Miloš , Míšek Jiří , Cvačka Josef , Rulíšek Lubomír , Chocholoušová Jana , Vacek Jaroslav , Goryl Grzegorz , Szymonski Marek , Císařová Ivana , Starý Ivo
Published: July 2009

Along with the recent progress in the development of advanced synthetic methods, the chemical community has witnessed an increasing interest in promising carbon-rich materials. Among them, helicenes are unique 3D aromatic systems that are inherently chiral and attractive for asymmetric catalysis, chiral recognition and material science. However, there have been only limited attempts at synthesizing long helicenes, which represent challenging targets. Here, we report on an organometallic approach to the derivatives of undecacyclic helicene, which is based on intramolecular [2 + 2 + 2] cycloisomerization of aromatic hexaynes under metal catalysis closing 6 new cycles of a helicene backbone in a single operation. The preparation of nonracemic compounds relied on racemate resolution or diastereoselective synthesis supported by quantum chemical (density functional theory) calculations. The fully aromatic [11]helicene was studied in detail including the measurement and theoretical calculation of its racemization barrier and its organization on the InSb (001) surface by STM. This research provides a strategy for the synthesis of long helical aromatics that inherently comprise 2 possible channels for charge transport: Along a π-conjugated pathway and across an intramolecularly π-π stacked aromatic scaffold.
Gourd and squash artifacts yield starch grains of feasting foods from preceramic Peru
Authors: Duncan Neil A. , Pearsall Deborah M. , Benfer Robert A.
Published: July 2009

In a study of residues from gourd and squash artifacts, we recovered starch grains from manioc (
Manihot esculenta), potato (Solanum
sp.), chili pepper (
Capsicum
spp.), arrowroot (
Maranta arundinacea
), and
algarrobo
(
Prosopis
sp.) from feasting contexts at the Buena Vista site, a central Peruvian preceramic site dating to ≈2200 calendar years B.C. This study has implications for the study of plant food use wherever gourds or squashes are preserved, documents the earliest evidence for the consumption of
algarrobo
and arrowroot in Peru, and provides insights into foods consumed at feasts.
A single-cell pedigree analysis of alternative stochastic lymphocyte fates
Authors: Hawkins E. D. , Markham J. F. , McGuinness L. P. , Hodgkin P. D.
Published: July 2009

In contrast to most stimulated lymphocytes, B cells exposed to Toll-like receptor 9 ligands are nonself-adherent, allowing individual cells and families to be followed in vitro for up to 5 days. These B cells undergo phases typical of an adaptive response, dividing up to 6 times before losing the impetus for further growth and division and eventually dying by apoptosis. Using long-term microscopic imaging, accurate histories of individual lymphocyte fates were collected. Quantitative analysis of family relationships revealed that times to divide of siblings were strongly related but these correlations were progressively lost through consecutive divisions. A weaker, but significant, correlation was also found for death times among siblings. Division cessation is characterized by a loss of cell growth and the division in which this occurs is strongly inherited from the original founder cell and is related to the size this cell reaches before its first division. Thus, simple division-based dilution of factors synthesized during the first division may control the maximum division reached by stimulated cells. The stochastic distributions of times to divide, times to die, and divisions reached are also measured. Together, these results highlight the internal cellular mechanisms that control immune responses and provide a foundation for the development of new mathematical models that are correct at both single-cell and population levels.
The kuru infectious agent is a unique geographic isolate distinct from Creutzfeldt–Jakob disease and scrapie agents
Authors: Manuelidis Laura , Chakrabarty Trisha , Miyazawa Kohtaro , Nduom Nana-Aba , Emmerling Kaitlin
Published: July 2009

Human sporadic Creutzfeldt–Jakob disease (sCJD), endemic sheep scrapie, and epidemic bovine spongiform encephalopathy (BSE) are caused by a related group of infectious agents. The new U.K. BSE agent spread to many species, including humans, and clarifying the origin, specificity, virulence, and diversity of these agents is critical, particularly because infected humans do not develop disease for many years. As with viruses, transmissible spongiform encephalopathy (TSE) agents can adapt to new species and become more virulent yet maintain fundamentally unique and stable identities. To make agent differences manifest, one must keep the host genotype constant. Many TSE agents have revealed their independent identities in normal mice. We transmitted primate kuru, a TSE once epidemic in New Guinea, to mice expressing normal and ≈8-fold higher levels of murine prion protein (PrP). High levels of murine PrP did not prevent infection but instead shortened incubation time, as would be expected for a viral receptor. Sporadic CJD and BSE agents and representative scrapie agents were clearly different from kuru in incubation time, brain neuropathology, and lymphoreticular involvement. Many TSE agents can infect monotypic cultured GT1 cells, and unlike sporadic CJD isolates, kuru rapidly and stably infected these cells. The geographic independence of the kuru agent provides additional reasons to explore causal environmental pathogens in these infectious neurodegenerative diseases.
InhibitingPlasmodium falciparumgrowth and heme detoxification pathway using heme-binding DNA aptamers
Authors: Niles Jacquin C. , DeRisi Joseph L. , Marletta Michael A.
Published: July 2009

The human parasitePlasmodium falciparumenzymatically digests hemoglobin during its intra-erythrocytic developmental stages in acidic food vacuole compartments. The released heme is rapidly detoxified by polymerization into the chemically inert pigment, hemozoin. Several heme-binding anti-malarial compounds, such as chloroquine, efficiently inhibit this process, and this is believed to be the predominant mechanism by which these drugs induce parasite toxicity. In an effort to expand the biochemical tools available for exploration of this pathogen's basic biology, we chose this heme-detoxification pathway as a model system for exploring the suitability of DNA aptamers for modulating this essential parasite biochemical pathway. In this report, we demonstrate that heme-binding DNA aptamers efficiently inhibit in vitro hemozoin formation catalyzed by either a model lipid system or parasite-derived extracts just as or more potently than chloroquine. Furthermore, when parasites are grown in red cells loaded with heme-binding aptamers, their growth is significantly inhibited relative to parasites exposed to non-heme-binding DNA oligonucleotides. Both the timing of parasite-induced toxicity and the concentration of heme-binding aptamer required for inducing toxicity correlate well with the uptake of red cell cytosolic components by the parasite, and the requirement for compounds with similar in vitro hemozoin inhibitory potency to preconcentrate within the parasite before observing toxicity. Thus, these heme-binding aptamers recapitulate the in vitro hemozoin inhibition activity and induce parasite toxicity in a manner consistent with inhibition of this pathway. Altogether, these data demonstrate that aptamers can be versatile tools with applicability in functionally dissecting importantP. falciparum-specific pathways both in vitro and in vivo.
Stomach ghrelin-secreting cells as food-entrainable circadian clocks
Authors: LeSauter Joseph , Hoque Nawshin , Weintraub Michael , Pfaff Donald W. , Silver Rae
Published: July 2009

Increases in arousal and activity in anticipation of a meal, termed “food anticipatory activity” (FAA), depend on circadian food-entrainable oscillators (FEOs), whose locations and output signals have long been sought. It is known that ghrelin is secreted in anticipation of a regularly scheduled mealtime. We show here that ghrelin administration increases locomotor activity in nondeprived animals in the absence of food. In mice lacking ghrelin receptors, FAA is significantly reduced. Impressively, the cumulative rise of activity before food presentation closely approximates a Gaussian function (
r
= 0.99) for both wild-type and ghrelin receptor knockout animals, with the latter having a smaller amplitude. For both groups, once an animal begins its daily anticipatory bout, it keeps running until the usual time of food availability, indicating that ghrelin affects response threshold. Oxyntic cells coexpress ghrelin and the circadian clock proteins PER1 and PER2. The expression of PER1, PER2, and ghrelin is rhythmic in light–dark cycles and in constant darkness with ad libitum food and after 48 h of food deprivation. In behaviorally arrhythmic-clock mutant mice, unlike control animals, there is no evidence of a premeal decrease in oxyntic cell ghrelin. Rhythmic ghrelin and PER expression are synchronized to prior feeding, and not to photic schedules. We conclude that oxyntic gland cells of the stomach contain FEOs, which produce a timed ghrelin output signal that acts widely at both brain and peripheral sites. It is likely that other FEOs also produce humoral signals that modulate FAA.
Basal lamina strengthens cell membrane integrity via the laminin G domain-binding motif of α-dystroglycan
Authors: Han Renzhi , Kanagawa Motoi , Yoshida-Moriguchi Takako , Rader Erik P. , Ng Rainer A. , Michele Daniel E. , Muirhead David E. , Kunz Stefan , Moore Steven A. , Iannaccone Susan T. , Miyake Katsuya , McNeil Paul L. , Mayer Ulrike , Oldstone Michael B. A. , Faulkner John A. , Campbell Kevin P.
Published: July 2009

Skeletal muscle basal lamina is linked to the sarcolemma through transmembrane receptors, including integrins and dystroglycan. The function of dystroglycan relies critically on posttranslational glycosylation, a common target shared by a genetically heterogeneous group of muscular dystrophies characterized by α-dystroglycan hypoglycosylation. Here we show that both dystroglycan and integrin α7 contribute to force-production of muscles, but that only disruption of dystroglycan causes detachment of the basal lamina from the sarcolemma and renders muscle prone to contraction-induced injury. These phenotypes of dystroglycan-null muscles are recapitulated by

Large
myd

muscles, which have an intact dystrophin–glycoprotein complex and lack only the laminin globular domain-binding motif on α-dystroglycan. Compromised sarcolemmal integrity is directly shown in

Large
myd

muscles and similarly in normal muscles when arenaviruses compete with matrix proteins for binding α-dystroglycan. These data provide direct mechanistic insight into how the dystroglycan-linked basal lamina contributes to the maintenance of sarcolemmal integrity and protects muscles from damage.
Conformational heterogeneity of the M2 proton channel and a structural model for channel activation
Authors: Yi Myunggi , Cross Timothy A. , Zhou Huan-Xiang
Published: July 2009

The M2 protein of influenza virus A is a proton-selective ion channel activated by pH. Structure determination by solid-state and solution NMR and X-ray crystallography has contributed significantly to our understanding, but channel activation may involve conformations not captured by these studies. Indeed, solid-state NMR data demonstrate that the M2 protein possesses significant conformational heterogeneity. Here, we report molecular dynamics (MD) simulations of the M2 transmembrane domain (TMD) in the absence and presence of the antiviral drug amantadine. The ensembles of MD conformations for both apo and bound forms reproduced the NMR data well. The TMD helix was found to kink around Gly-34, where water molecules penetrated deeply into the backbone. The amantadine-bound form exhibited a single peak ≈10° in the distribution of helix-kink angle, but the apo form exhibited 2 peaks, ≈0° and 40°. Conformations of the apo form with small and large kink angles had narrow and wide pores, respectively, around the primary gate formed by His-37 and Trp-41. We propose a structural model for channel activation, in which the small-kink conformations dominate before proton uptake by His-37 from the exterior, and proton uptake makes the large-kink conformations more favorable, thereby priming His-37 for proton release to the interior.
Post-war Ethiopia: The Trajectories of Crisis
Authors: Clapham Christopher
Published: July 2009

This article addresses current crises of governance in Ethiopia. Internal conflicts within the ruling coalition arise from its origins in a localised insurgency and its flawed capacity to create a broader political base. In the national context, particularly in the major towns, it rules only by effective force and not through dialogue or negotiation. A policy of ethnic federalism promised devolution of powers to local areas, but founders on the difficulty of reconciling autonomous systems of power and authority within a common political structure. Internationally, Ethiopia has had considerable success, presenting itself as a model of ‘good governance’ with donor approval. Having accepted the basic tenets of neoliberalism, it also backed the ‘global war on terror’, giving it scope to promote its own agenda, with US backing, in Somalia. Its cardinal problem remains the management of diversity and opposition.
The End of Democracy? Curtailing Political and Civil Rights in Ethiopia
Authors: Aalen Lovise , Tronvoll Kjetil
Published: July 2009

This article assesses political developments in Ethiopia after its 2005 federal and regional watershed elections. Although an unprecedented liberalisation took place ahead of the contested and controversial 2005 polls, a crack-down occurred in the wake of the elections, when the opposition was neutralised. Subsequently, the government rolled out a deliberate plan to prevent any future large-scale protest against their grip on power by establishing an elaborate administrative structure of control, developing new legislative instruments of suppression and, finally, curbing any electoral opposition as seen in the conduct of the 2008 local elections. As a result, Ethiopia has by 2008 returned firmly into the camp of authoritarian regimes.
The Politics of Silence: Interpreting Stasis in Contemporary Eritrea
Authors: Reid Richard
Published: July 2009

This article examines the current stand-off between the Eritrean government and the broader population, with an appreciation of the historical dynamics that have influenced the contemporary situation. It is argued here that although little appears to be changing in Eritrea on the surface, subtle but important shifts in attitude are taking place, both within government and among the broader populace. The article explores contemporary political culture in Eritrea, including the system which has developed around the position of the President Isaias Afwerki, and in particular focuses on the marked degree of militarisation which now characterises Eritrean society. Specifically, education has now become highly militarised, while the issue of the ‘demarcation’ of the border with Ethiopia – a key issue since the ceasefire in 2000 – has wider implications for future relations between government and people.
How Liberal Peacebuilding May Be Failing Sierra Leone
Authors: Castañeda Carla
Published: July 2009

The concept of security is the driver for peacebuilding and development, as well as social and political change in post-conflict countries. A review and analysis of three key government documents indicates that, in Sierra Leone, securitisation discourse is embedded in both the political economy discourse of the state and in the popular imagination. The Security Sector Review equates security and peace while the country's Poverty Reduction Strategy Paper sees security as a driver for change. The 2006 Work Plan of the Ministry of Agriculture, Forestry and Food Security illustrates the extent to which the work of ministries is security-based. Sierra Leone's political economy of post-conflict peacebuilding favours macro-economic security that is to trickle down into social and political peace. Discourse analysis shows that, framed within security parameters, post-conflict peacebuilding is meant to have an effect of ‘trickle-down peace’ that in effect constrains transformation with the potential for facilitating conditions for a return to conflict.
The Ethiopia–Eritrea Conflict and the Search for Peace in the Horn of Africa
Authors: Lyons Terrence
Published: July 2009

The Ethiopia-Eritrea border dispute is embedded within a set of domestic political conflicts in each state, is linked further through proxy conflicts to instability in Somalia and the Ogaden, and is skewed additionally by the application of Washington's global counter-terrorism policies to the region. Each of these arenas of contention has its own history, issues, actors and dynamic; however, each is also distorted by processes of conflict escalation and de-escalation in the other arenas. The intermeshing of domestic insecurities, interstate antagonisms, and global policies create regional ‘security complexes’ in which the security of each actor is intrinsically linked to the others and cannot realistically be considered apart from one another. Prospects for both the escalation and resolution of the Ethiopia-Eritrea conflict are linked to domestic political processes (such as increasing authoritarianism), regional dynamics (such as local rivalries played out in Somalia) and international policies (such as US counter-terrorism policies).
Somalia: ‘They Created a Desert and Called it Peace(building)’
Authors: Menkhaus Ken
Published: July 2009

This article documents the humanitarian, political and security dimensions of the current Somali crisis and assesses the external policies that are playing an increasingly central role in the conflict. It advances the thesis that in 2007 and 2008 external Western and UN actors treated Somalia as a post-conflict setting when in fact their own policies helped to inflame armed conflict and insecurity there. As a result there was no peace for peacekeepers to keep, no state to which state-building projects could contribute, and increasingly little humanitarian space in which aid agencies could reach over 3 million Somalis in need of emergency relief. The gap between Somali realities on the ground and the set of assumptions on which aid and diplomatic policies toward Somalia have been constructed is wide and deep.
Revisiting Pedagogy of the Oppressed: Paulo Freire and Contemporary African Studies
Authors: Thomas David
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Published: July 2009

The purpose of this article is to (re)introduce Paulo Freire's Pedagogy of the Oppressed to the study of contemporary African societies. Widely accepted as foundational work in the field of critical pedagogy, it is argued that Freirean scholarship and analysis is also useful in examining the top-down manner in which ‘development’ is currently being implemented on the continent. By examining the case of post-apartheid South Africa, this article posits that a Freirean understanding of liberation/freedom as a dialogical exercise can aid in opening up a productive avenue of critical enquiry regarding the post-colonial condition in sub-Saharan Africa. This analysis will use Freire's theoretical work in order to contribute to the literature regarding possibilities for more participatory, democratic and bottom-up struggles for social justice.
Heresy and heroics: The debate on the alleged ‘crisis’ in Italian industrial design around 1960
Authors: Fallan Kjetil
Published: July 2009

In the course of the 1950s, Italian industrial design underwent a period of professionalisation and rose to international fame under the banners of ‘Made in Italy’ and ‘la linea italiana’. Seen in retrospect, Italian design retained this position during the 1960s, with the onset of avant-garde ‘pop-design’ and ‘anti-design’. Yet this future development was by no means a given in the Italian design community at the turn of the decade. At this crucial moment, between the rationality of the first postwar period and the playfulness of the second, allegations of a ‘crisis’ in Italian industrial design raised a storm in the professional community for a brief period around 1960. This article analyses this heated debate, focusing on its most pronounced manifestation: the discussions in the Associazione per il Disegno Industriale (ADI) and the design magazineStile Industriafollowing the jury's decision to withhold the Gran Premio Nazionale Compasso d'Oro for 1959.
Processes of institutionalisation and ‘symbolic struggles’ in the ‘independent music’ field in Italy
Authors: Magaudda Paolo
Published: July 2009

Over the last fifteen years, independent rock music has become a wider field of cultural production and consumption in Italy. Indeed, while during the 1970s and 1990s the production of independent music was connected predominantly to political movements, alternative subcultures and the antagonistic attitude of the ‘centri sociali’, in the present decade, independent popular music has moved towards the centre of the national music industry and the mass media of the musical mainstream. This article describes the phases of this process of institutionalisation, showing how the politically based culture of independent music is today at the centre of a symbolic struggle occurring between the values of authenticity, rooted in political youth cultures, and the strategic and pragmatic tendency towards integration into the mainstream of the national music industry. This analysis is carried out applying the Bourdieian concepts of ‘field of cultural production’ and ‘cultural capital’, together with their evolutions into the notion of ‘subcultural capital’. This theoretical framework is applied in order to show both the process of institutionalisation this cultural field is undergoing, and the symbolic struggle taking place between the original values of the political and cultural autonomy of music and the commoditisation of musical objects in the mainstream mass media and national industrial sector. Finally, it is shown how new agents who represent the independent popular music industry at the national level need to deal with claims for authenticity raised by the alternative and extreme wings of the independent music scene.
From the other shore: American political science and the ‘Italian case’
Authors: Mastropaolo Alfio
Published: July 2009

This article examines a number of the major works on Italy conducted by political scientists from the United States in the second half of the twentieth century. Focusing on the research of Banfield, Almond and Verba, Tarrow and Putnam, it discusses the interpretations of Italy offered by these scholars and examines the contribution they have made to the political and intellectual debate surrounding the so-called ‘Italian case’. It concludes that the image presented of Italy by American researchers is generally critical and often simplified and stereotypical. Moreover, rather than highlighting the clichés frequently present in such accounts, Italian intellectuals have tended instead to use them in order to construct a wholly negative perspective of Italy and, in many instances, have distorted the original intentions of those American political scientists whose work is cited as evidence.
Scholarly formulations of a political category: Clientelism and the sociohistorical interpretation of the ‘Italian case’
Authors: Briquet Jean-Louis
Published: July 2009

This article reflects on the reasons why clientelism has reached its status as a determining category in the scholarly interpretation of the Italian political system. By returning to the earliest formulations of the concept (in the controversies of the late nineteenth century on the widening of suffrage) and then its successive recreations up to the political crisis of the 1990s (as a typical manifestation of the political ‘anomalies’ of an ‘incomplete’ democracy), it relates this centrality to the uses made of the denunciation of clientelism in political and institutional struggles and the way political science has developed in Italy as an academic discipline.
The ‘revolution that never was’: Rai-TV and the launch of Tribuna politica
Authors: Guazzaloca Giulia
Published: July 2009

This article examines the launch of the Tribuna elettorale and Tribuna politica programmes on Italian television (1960–1961), seen in the context of the country's broadcasting history and the changes in the political spectrum and governing alliances at that time. The changing face of political communications and leader–viewer relations may be the most interesting side to the Tribune, but also the most heavily studied. This article chooses instead to reconstruct the steps and reasons that led prime minister Fanfani in the autumn of 1960 to force through his decision to give all political parties airspace for political propaganda. The article argues that the Tribune programmes were only partly innovatory, a kind of ‘revolution that never was’. They were a first step towards democratising the public broadcasting corporation, but maintained firm links with the past and above all sought to legitimiste ‘government television’, as well as delaying structural reform of the medium in the face of mounting pressure on many sides. For the Christian Democrat (DC) and the RAI management, the Tribune programmes were a clever compromise solution, giving in terms of pluralism of information what they were not prepared to concede in terms of pluralism of management.