bluuebunny/crossref_metadata_2025 huggingface dataset:
Changing household responses to drought in Tharaka, Kenya: vulnerability, persistence and challenge
Authors: Smucker Thomas A. , Wisner Ben
Published: April 2008

Drought is a recurring challenge to the livelihoods of those living in Tharaka District, Kenya, situated in the semi‐arid zone to the east of Mount Kenya, from the lowest slopes of the mountain to the banks of the Tana River. This part of Kenya has been marginal to the economic and political life of Kenya from the colonial period until the present day. A study of more than 30 years of change in how people in Tharaka cope with drought reveals resilience in the face of major macro‐level transformations, which include privatisation of landownership, population growth, political decentralisation, increased conflict over natural resources, different market conditions, and environmental shifts. However, the study also shows troubling signs of increased use of drought responses that are incompatible with long‐term agrarian livelihoods. Government policy needs to address the challenge of drought under these new macro conditions if sustainable human development is to be achieved.
Estimating the Basic Reproductive Number in the General Epidemic Model with an Unknown Initial Number of Susceptible Individuals
Authors: LAU ERIC H. Y. , YIP PAUL S. F.
Published: April 2008

Abstract. In any epidemic, there may exist an unidentified subpopulation which might be naturally immune or isolated and who will not be involved in the transmission of the disease. Estimation of key parameters, for example, the basic reproductive number, without accounting for this possibility would underestimate the severity of the epidemics. Here, we propose a procedure to estimate the basic reproductive number (R0) in an epidemic model with an unknown initial number of susceptibles. The infection process is usually not completely observed, but is reconstructed by a kernel‐smoothing method under a counting process framework. Simulation is used to evaluate the performance of the estimators for major epidemics. We illustrate the procedure using the Abakaliki smallpox data.
An open‐label pilot study of alefacept for the treatment of pyoderma gangrenosum
Authors: Foss CE , Clark AR , Inabinet R , Camacho F , Jorizzo JL
Published: April 2008

Background  Pyoderma gangrenosum (PG) is a chronic inflammatory disease that causes painful cutaneous ulcers that are difficult to treat. Currently, systemic immunosuppressants, often including prednisone, are the mainstay of therapy. Long‐term therapy with these agents is often required which exposes patients to possible adverse effects. An alternative treatment that is safe and effective is truly needed.

Objective  To study the efficacy and safety of alefacept, which inhibits T‐cell activation and selectively reduces the T‐cell population, for treatment of PG.

Method  In this prospective open‐label pilot study, four patients diagnosed with PG received weekly doses of 15 mg alefacept intramuscularly for 20 weeks with 12‐week treatment‐free follow‐up. The primary efficacy end point was the proportion of patients achieving remission as defined by a Physician Global Assessment (PGA) of ‘clear’ or ‘almost clear.’ Secondary endpoints included proportion of patients achieving 50% improvement in PG lesion size (measured in mm) and proportion of patients achieving resolution of inflammation (an erythema score of 0 and a border thickness of 0 on scales of 0–4).

Results  By week 20, one (25%) of the four patients achieved remission, two showed marked improvement in severity on PGA, and one had slight improvement. One patient showed a 98% decrease in lesion size; two other patients evidenced a decrease in the number of small lesions as well as improvements in primary lesion sizes, but did not surpass the 50% criterion. All four patients showed improved erythema scores during treatment, though only one patient showed a complete resolution of inflammation.

Limitations  It may be difficult to generalize the results of this study to a larger population of patients with PG due to the small sample size and lack of a control group. A longer treatment interval might have been required. Safety and efficacy of long‐term therapy is unknown.

Conclusion  In this pilot study it appears that alefacept treatment may significantly reduce PG severity levels as evidenced by improvement in PGA, Subject Global Assessment, and inflammation scores in all patients. Alefacept may be a safe and effective alternative to current systemic immunosuppressants used to treat PG. Double‐blinded, controlled trials are necessary to further evaluate the safety and effectiveness of this treatment.
Alopecia areata in Turkey: demographic and clinical features
Authors: Kavak A , Yeşildal N , Parlak AH , Gökdemir G , Aydoǧan İ , Anul H , Baykal C
Published: April 2008

Background  Alopecia areata is a complex genetic disease with still many unknown aspects, and many studies have been tried to find some clues about it.

Objective  We aimed to investigate the demographic and clinical characteristics of alopecia areata in Turkish patients.

Methods  Demographic data, localization, attack number in addition to some parameters such as disease duration, severity, age of onset, family history and ophiasis pattern were evaluated in 539 alopecia areata patients.

Results  The male to female ratio was 1.6 : 1. Occipital and beard‐moustache areas were mostly affected. Positive family history was noticed in 24.1% of the patients. The age of onset was earlier in women than in men (P = 0.04). Severe forms showed more persistent (≥ 1 year) disease duration (P = 0.00). Ophiasis was more common in severe, long duration (≥ 1 year) and early onset (≤ 18 years) disease (P = 0.00 for all parameters). Childhood alopecia areata (≤ 18 years) was also associated with long duration of the disease (P = 0.016) and positive family history (P = 0.008) when compared with adult onset (> 18 years) alopecia areata.
Serologic markers of celiac disease in psoriatic patients
Authors: Damasiewicz‐Bodzek A , Wielkoszyński T
Published: April 2008

Background  Aetiopathogenesis of psoriasis is complex and not yet well known. In recent years, it has been observed that psoriasis can coexist with clinically asymptomatic celiac disease and a gluten‐free diet helps to obtain remission, even in patients with very chronic lesions.

Objective  The aim of our work was to investigate how often the positive titres of antibodies characteristic for celiac disease occur in psoriatics’ serum in exacerbation in comparison with controls.

Patients/methods  Serum samples from 67 patients with intensified psoriatic lesions were investigated. Serum from healthy people at a comparable age and with no familial predisposition to psoriasis and celiac disease was the control material. Antibodies against human tissue transglutaminase (recombinant antigen), against tissue transglutaminase isolated from guinea pig's liver and against gliadin were determined by enzyme‐linked immunosorbent assay technique. Anti‐endomysial antibodies were determined by indirect immunofluorescence method.

Results  Patients with psoriasis have significantly higher mean concentrations of antibodies against tissue transglutaminase (human recombinant and guinea pig‐derived antigen) and against gliadin for IgA. IgA antibodies against tissue transglutaminase (both antigens) and gliadin positively correlate with psoriasis activity. No anti‐endomysial antibodies for IgA were found in any serum.

Conclusions  Our results seem to imply an association between psoriasis and asymptomatic celiac disease/gluten intolerance. High percentage of positive results to guinea pig‐derived tTG could be due to cellular activity of tissue transglutaminase in psoriasis.
A randomized, double‐blind study to assess the efficacy of addition of tetracycline to triamcinolone acetonide in the treatment of moderate to severe atopic dermatitis
Authors: Schuttelaar MLA , Coenraads PJ
Published: April 2008

Objective  To assess the efficacy of tetracycline in triamcinolone acetonide ointment compared with triamcinolone acetonide ointment in patients with moderate to severe atopic dermatitis.

Design  Randomised, double‐blind parallel group study of 8 weeks’ duration.

Setting  Outpatient clinic in a university hospital.

Participants  Forty‐four adult patients with moderate to severe atopic dermatitis (objective SCORAD > 25).

Interventions  Initial phase (2 weeks): 3% tetracycline 0.1% triamcinolone acetonide vs. 0.1% triamcinolone acetonide twice daily all over the body.

Maintenance phase (6 weeks)  0.1% triamcinolone acetonide once daily for 2 weeks, followed by every other day for 2 weeks. In the last 2 weeks, two applications a week were done. An emollient was used additionally once daily.

Main outcome measures  Primary outcomes were the disease severity scores assessed by objective SCORAD and SASSAD at week 2. Secondary outcomes were the objective SCORAD and SASSAD at weeks 4 and 8, and Staphylococcus aureus colonization at weeks 0 and 2.

Results  No significant differences in disease severity outcomes were found between the two groups. Both groups showed clinically relevant improvements in disease severity compared with baseline at weeks 2 and 4. At week 8, there was some worsening in disease severity in both groups, but the disease severity was still significantly lower than at the beginning of the study. Improvement of bacterial colonization was seen in 14 (63.6%) out of the 22 patients in the 3% tetracycline 0.1% triamcinolone acetonide group and in 5 (22.7%) out of the 22 patients in the 0.1% triamcinolone acetonide group.

Conclusion  The addition of tetracycline was effective on skin colonization by S. aureus but did in our patients with atopic dermatitis not result in a significantly different improvement compared with the group treated without tetracycline.
‘When Your Child Dies You Don’t Belong in That World Any More’– Experiences of Mothers Whose Child with an Intellectual Disability has Died
Authors: Reilly Deirdre E. , Huws Jaci C. , Hastings Richard P. , Vaughan Frances L.
Published: April 2008

Background  Individuals with intellectual disability are at higher risk of premature death compared with individuals without intellectual disability, and therefore parents of people with intellectual disability are more likely to outlive their children. However, there has been relatively little research investigating the bereavement experiences of parents of deceased children with intellectual disability.

Method  Semi‐structured interviews were used to explore the experiences of nine mothers whose child with intellectual disability had died. The transcripts were analysed qualitatively using Interpretative Phenomenological Analysis.

Results  Five themes emerged from the analysis: loss, benefit finding, coping, sources of support and medical relationships. An analysis of the accounts indicated similarities and differences between the experiences of the mothers. In particular, continuing in their caring role by working within the world of intellectual disability following the death of their child was important to all of the mothers. Support from similarly bereaved parents was the most useful source of support, although it was not always readily accessible.

Conclusions  Implications for theory and practice are described including suggestions that service providers should aim to maintain links with families after the death of their child, a parent‐to‐parent programme that enables parents to contact others in a similar situation might be beneficial, and further research into the functions of coping strategies and supports in loss would be worthwhile.
The evolutionary history of the hominin hand since the last common ancestor of Pan and Homo
Authors: Tocheri Matthew W. , Orr Caley M. , Jacofsky Marc C. , Marzke Mary W.
Published: April 2008

Molecular evidence indicates that the last common ancestor of the genus Pan and the hominin clade existed between 8 and 4 million years ago (Ma). The current fossil record indicates the Pan‐Homo last common ancestor existed at least 5 Ma and most likely between 6 and 7 Ma. Together, the molecular and fossil evidence has important consequences for interpreting the evolutionary history of the hand within the tribe Hominini (hominins). Firstly, parsimony supports the hypothesis that the hand of the last common ancestor most likely resembled that of an extant great ape overall (Pan, Gorilla, and Pongo), and that of an African ape in particular. Second, it provides a context for interpreting the derived changes to the hand that have evolved in various hominins. For example, the Australopithecus afarensis hand is likely derived in comparison with that of the Pan–Homo last common ancestor in having shorter fingers relative to thumb length and more proximo‐distally oriented joints between its capitate, second metacarpal, and trapezium. This evidence suggests that these derived features evolved prior to the intensification of stone tool‐related hominin behaviors beginning around 2.5 Ma. However, a majority of primitive features most likely present in the Pan‐Homo last common ancestor are retained in the hands of Australopithecus, Paranthropus/early Homo, and Homo floresiensis. This evidence suggests that further derived changes to the hands of other hominins such as modern humans and Neandertals did not evolve until after 2.5 Ma and possibly even later than 1.5 Ma, which is currently the earliest evidence of Acheulian technology. The derived hands of modern humans and Neandertals may indicate a morphological commitment to tool‐related manipulative behaviors beyond that observed in other hominins, including those (e.g. H. floresiensis) which may be descended from earlier tool‐making species.
The environmental context of human evolutionary history in Eurasia and Africa
Authors: Elton Sarah
Published: April 2008

This review has three main aims: (1) to make specific predictions about the habitat of the hypothetical last common ancestor of the chimpanzee/bonobo–human clade; (2) to outline the major trends in environments between 8–6 Ma and the late Pleistocene; and (3) to pinpoint when, and in some cases where, human ancestors evolved to cope with the wide range of habitats they presently tolerate. Several lines of evidence indicate that arboreal environments, particularly woodlands, were important habitats for late Miocene hominids and hominins, and therefore possibly for the last common ancestor of the chimpanzee/bonobo–human clade. However, as there is no clear candidate for this last common ancestor, and because the sampling of fossils and past environments is inevitably patchy, this prediction remains a working hypothesis at best. Nonetheless, as a primate, it is expected that the last common ancestor was ecologically dependent on trees in some form. Understanding past environments is important, as palaeoenvironmental reconstructions provide the context for human morphological and behavioural evolution. Indeed, the impact of climate on the evolutionary history of our species has long been debated. Since the mid‐Miocene, the Earth has been experiencing a general cooling trend accompanied by aridification, which intensified during the later Pliocene and Pleistocene. Numerous climatic fluctuations, as well as local, regional and continental geography that influenced weather patterns and vegetation, created hominin environments that were dynamic in space and time. Behavioural flexibility and cultural complexity were crucial aspects of hominin expansion into diverse environments during the Pleistocene, but the ability to exploit varied and varying habitats was established much earlier in human evolutionary history. The development of increasingly complex tool technology facilitated re‐expansion into tropical forests. These environments are difficult for obligate bipeds to negotiate, but their exploitation was accomplished by archaic and/or anatomically modern humans independently in Africa and south‐east Asia. Complex social behaviour and material culture also allowed modern humans to reach some of the most hostile regions of the globe, above the Arctic Circle, by the late Pleistocene. This, with colonization of the Americas and Australasia, establishedHomo sapiensas a truly cosmopolitan species.
Inferences regarding the diet of extinct hominins: structural and functional trends in dental and mandibular morphology within the hominin clade
Authors: Lucas Peter W. , Constantino Paul J. , Wood Bernard A.
Published: April 2008

This contribution investigates the evolution of diet in the Pan–Homo and hominin clades. It does this by focusing on 12 variables (nine dental and three mandibular) for which data are available about extant chimpanzees, modern humans and most extinct hominins. Previous analyses of this type have approached the interpretation of dental and gnathic function by focusing on the identification of the food consumed (i.e. fruits, leaves, etc.) rather than on the physical properties (i.e. hardness, toughness, etc.) of those foods, and they have not specifically addressed the role that the physical properties of foods play in determining dental adaptations. We take the available evidence for the 12 variables, and set out what the expression of each of those variables is in extant chimpanzees, the earliest hominins, archaic hominins, megadont archaic hominins, and an inclusive grouping made up of transitional hominins and pre‐modern Homo. We then present hypotheses about what the states of these variables would be in the last common ancestor of the Pan–Homo clade and in the stem hominin. We review the physical properties of food and suggest how these physical properties can be used to investigate the functional morphology of the dentition. We show what aspects of anterior tooth morphology are critical for food preparation (e.g. peeling fruit) prior to its ingestion, which features of the postcanine dentition (e.g. overall and relative size of the crowns) are related to the reduction in the particle size of food, and how information about the macrostructure (e.g. enamel thickness) and microstructure (e.g. extent and location of enamel prism decussation) of the enamel cap might be used to make predictions about the types of foods consumed by extinct hominins. Specifically, we show how thick enamel can protect against the generation and propagation of cracks in the enamel that begin at the enamel–dentine junction and move towards the outer enamel surface.
PPAR: a therapeutic target in Parkinson’s disease
Authors: Chaturvedi Rajnish K. , Beal M. Flint
Published: April 2008

Parkinson’s disease (PD) is a progressive and chronic neurodegenerative disorder, characterized by progressive loss of dopaminergic neurons in substantia nigra. The etiology and pathogenesis of PD is still elusive, however, a large body of evidence suggests a prominent role of oxidative stress, inflammation, apoptosis, mitochondrial dysfunction and proteosomal dysfunction in the pathogenesis of PD. Due to multifactorial nature of the disease, currently available drug therapy cannot halt / slow down the disease progression, and only provides symptomatic relief. Peroxisome proliferator‐activated receptor (PPAR), a member of nuclear receptor superfamily, regulates development, tissue differentiation, inflammation, mitochondrial function, wound healing, lipid metabolism and glucose metabolism. Recently, several PPAR agonists were shown to exert neuroprotective activity against oxidative damage, inflammation and apoptosis in several neurodegenerative disorders including Alzheimer’s, Parkinson’s, Huntington’s, amyotrophic lateral sclerosis and multiple sclerosis. Similarly, regular intake of PPAR activating non‐steroidal anti‐inflammatory drugs such as indomethacin and ibuprofen was associated with reduced incidence and progression of neurodegenerative disorders in several epidemiological studies. In this article, we review studies relating to the neuroprotective effect of PPAR agonists in in vitro and in vivo models of PD. Similarly, the pharmacological mechanism in neuroprotective actions of PPAR agonists is also reviewed. In conclusion, PPAR agonists exert neuroprotective actions by regulating the expression of a set of genes involved in cell survival processes, and could be a therapeutic target in debilitating neurodegenerative illnesses such as PD.
The spatialities of contentious politics
Authors: Leitner Helga , Sheppard Eric , Sziarto Kristin M.
Published: April 2008

The question of how space matters to the mobilisation, practices and trajectories of contentious politics has frequently been represented as a politics of scale. Others have focused on place and networks as key spatialities of contentious politics. Yet there are multiple spatialities – scale, place, networks, positionality and mobility – that are implicated in and shape contentious politics. No one of these should be privileged: in practice, participants in contentious politics frequently draw on several at once. It is thus important to consider all of them and the complex ways in which they are co‐implicated with one another, with unexpected consequences for contentious politics. This co‐implication in practice, and its impact on social movements, is illustrated with the Immigrant Workers’ Freedom Ride in the United States.
Mountains and memory: embodied visions of ancient peaks in the nineteenth‐century Aegean
Authors: Della Dora Veronica
Published: April 2008

Over the past few years, the relationship between landscape and the body as two physical entities mutually informed through performance has been increasingly interrogated by cultural geographers. Similar issues about memory, embodiment and performativity have been raised in the social sciences, yet often obliterating the material specificities of place and landscape. This paper reconsiders the relationship between landscape and memory in terms of embodied, visual and spatial practice, rather than as a contested cultural politics of heritage and identity (as it has been generally understood in cultural geography after the so‐called ‘cultural turn’). Drawing on Nora's ‘memory places’ and on the Deleuzian notion of ‘ontological past’, as well as on recent writing on historical geographies of exploration and travel, the paper explores the spatial re‐activation of Classical historical memory by nineteenth‐century British officers and travellers to Aegean mountain peaks through their embodied and site‐located practices of climbing, surveying or simply ‘gazing’.
Variations in cross‐cultural perception of riverscapes in relation to in‐channel wood
Authors: Le Lay Yves‐François , Piégay Hervé , Gregory Ken , Chin Anne , Dolédec Sylvain , Elosegi Arturo , Mutz Michael , Wyżga Bartłomiej , Zawiejska Joanna
Published: April 2008

Human perception of riverscapes with and without large wood (LW) has been investigated with a photo‐questionnaire submitted to 2250 students in ten countries, capturing reactions to 20 pictures in terms of naturalness, danger, aesthetics and need for improvement. Principal component analysis performed on average scores per country per item showed that the primary discriminating factors are human modification, turbulence and extent of water shown in the scenes. Wood discriminated the perception of student groups, but other factors are also critical. Features associated with human activity (channel deepening and straightening, rip‐rapping) were perceived to be less aesthetically pleasing than wood. Perception of the most dangerous riverscapes is not specifically affected by wood, but by turbulent flows and wide rivers. The presence of wood clearly discriminated the need for human intervention. Perceptions differed among countries, reflecting different cultural contexts. Students from Germany, Sweden and Oregon perceived LW more positively as a natural and wild component of watercourses. These perceptions are linked to positive attitudes towards natural riverscapes. Other students, such as those from China, Russia or India, perceived rivers with wood as needing regulation and maintenance. Whatever the socio‐cultural context, large wood elicits an emotional influence on how one perceives riverscapes.
Political affects in public space: normative blind‐spots in non‐representational ontologies
Authors: Barnett Clive
Published: April 2008

Recent theoretical debates in human geography have been characterised by a preference for ontological styles of argument. The ontologisation of theory is associated with distinctive claims about rethinking ‘the political’. This paper draws on an avowedly ‘non‐representationalist’ philosophical perspective to develop an interpretation of ontology‐talk as a genre that provides reasons for certain commitments. This argument is developed with reference to recent accounts of the spatial politics of affect in cultural geography and urban studies, and of the neuropolitics of media affects in political theory. The commitments that the ontology of affect provides reasons for are shown to revolve around understandings of the value of democracy. Assertions of the political relevance of ontologies of affect rhetorically appeal to norms that are not explicitly avowed from these theoretical perspectives. The ontologisation of affect depends on a particular settlement of the priority‐claims of different families of concepts. The combination of an ontological style of theoretical analysis and an imperative to claim relevance for affective aspects of life in terms of rethinking ‘the political’ leads to a presentation of affect as an effective modality of manipulation mediated by infrastructures of public space. The ontological presentation of affect therefore forecloses on a series of normative questions provoked by the acknowledgement of the affective aspects of life. While the value of democracy is thrown into new relief by affect onto‐stories, the full implications of any likely reconfiguration of our understandings of democracy remain to be elaborated in this line of thought, not least because it avoids any engagement with the principle of participation by all affected interests.
Racial/Ethnic Disparities in Knowledge about Risks and Benefits of Breast Cancer Treatment: Does It Matter Where You Go?
Authors: Hawley Sarah T. , Fagerlin Angela , Janz Nancy K. , Katz Steven J.
Published: April 2008

Objective. To evaluate the association between provider characteristics and treatment location and racial/ethnic minority patients' knowledge of breast cancer treatment risks and benefits.

Data Sources/Data Collection. Survey responses and clinical data from breast cancer patients of Detroit and Los Angeles SEER registries were merged with surgeon survey responses (N=1,132 patients, 277 surgeons).

Study Design. Cross‐sectional survey. Multivariable regression was used to identify associations between patient, surgeon, and treatment setting factors and accurate knowledge of the survival benefit and recurrence risk related to mastectomy and breast conserving surgery with radiation.

Principal Findings. Half (51 percent) of respondents had survival knowledge, while close to half (47.6 percent) were uncertain regarding recurrence knowledge. Minority patients and those with lower education were less likely to have adequate survival knowledge and more likely to be uncertain regarding recurrence risk than their counterparts (p<.001). Neither surgeon characteristics nor treatment location attenuated racial/ethnic knowledge disparities. Patient–physician communication was significantly (p<.001) associated with both types of knowledge, but did not influence racial/ethnic differences in knowledge.

Conclusions. Interventions to improve patient understanding of the benefits and risks of breast cancer treatments are needed across surgeons and treatment setting, particularly for racial/ethnic minority women with breast cancer.
Cognitive, Functional, and Quality‐of‐Life Outcomes of Patients Aged 80 and Older Who Survived at Least 1 Year After Planned or Unplanned Surgery or Medical Intensive Care Treatment
Authors: De Rooij Sophia E. J. A. , Govers Annerike C. , Korevaar Johanna C. , Giesbers Arja W. , Levi Marcel , De Jonge Evert
Published: April 2008

OBJECTIVES: To investigate long‐term cognitive, functional, and quality‐of‐life outcomes in very elderly survivors at least 1 year after planned or unplanned surgery or medical intensive care treatment.

DESIGN: Retrospective cohort study.

SETTING: General, 1,024‐bed, tertiary university teaching hospital in the Netherlands.

PARTICIPANTS: Two hundred four survivors of a cohort of 578 patients admitted to the medical–surgical intensive care unit (ICU) between January 1997 and December 2002 and alive in December 2003. The majority of survivors underwent elective surgery.

MEASUREMENTS: From December 2003 until February 2004, data were collected from 190 patients and 169 relatives. The measures were: Informant Questionnaire on Cognitive Decline short form (IQCODE‐SF) (cognition), modified Katz index of activities of daily living (ADLs) (functional status), and EuroQol (EQ‐5D) (health‐related quality of life). The patients themselves completed the modified Katz ADL index and EQ‐5D forms; their caregivers completed the ADL caregiver version and IQCODE‐SF.

RESULTS: The mean age at admission±standard deviation was 81.7±2.4, and the median time after discharge was 3.7 years (range 1–5.9 years). Of the ICU patients who had planned surgery, 57% survived, compared with 11% of the unplanned surgical admissions and 10% of the medical patients. Three‐quarters (74.3%) of the patients who lived at home before ICU admission remained at home at follow‐up. Eighty‐three percent had no severe cognitive impairment, and 76% had no severe physical limitations (33% had moderate, 40% had mild, and 3% had no limitations). The perceived quality of life was similar to that of an age‐matched general population.

CONCLUSION: Long‐term survivors of ICU treatment received at the age of 80 and older showed fair‐to‐good cognitive and physical functioning and quality of life, although few patients who underwent unplanned surgery or who were admitted to the ICU for medical reasons survived.
Type 2 Diabetes Mellitus and Cognitive Decline in Two Large Cohorts of Community‐Dwelling Older Adults
Authors: Okereke Olivia I. , Kang Jae H. , Cook Nancy R. , Gaziano J. Michael , Manson JoAnn E. , Buring Julie E. , Grodstein Francine
Published: April 2008

OBJECTIVES: To relate diabetes mellitus (DM) status and duration to late‐life cognitive impairment and decline in men and women.

DESIGN: Prospective cohort.

SETTING: Community.

PARTICIPANTS: Five thousand nine hundred seven men in the Physicians' Health Study II and 6,326 women in the Women's Health Study (mean age 74.1 and 71.9, respectively, at baseline cognitive assessment); 553 men and 405 women had DM.

MEASUREMENTS: Primary outcomes were general cognition (the Telephone Interview for Cognitive Status (TICS) and a global score averaging five tests) and verbal memory. All participants had second assessments approximately 2 years later; women had third assessments an average of 4 years later.

RESULTS: In adjusted linear regression models, participants with DM had significantly lower baseline scores for all outcomes, and longer duration of DM was associated with lower scores (P‐trends <.001). Men with DM had significantly greater 2‐year cognitive decline than men without DM, and longer duration of DM was associated with worse decline (P‐trends ≤.01). In repeated‐measures analyses of response profiles, women with DM had significantly greater 4‐year cognitive decline in all outcomes than women without DM. In women, as in men, there was generally greater cognitive decline with longer duration of DM (e.g., the adjusted mean difference in decline on the TICS associated with duration of ≥5 years was −0.74 (95% confidence interval=−1.05 to −0.43) points (P‐trend <.001). There were no significant sex–DM interactions.

CONCLUSION: Type 2 DM and longer duration of DM are similarly related to cognitive impairment and decline in men and women.
Empirical Evidence of Risk Shifting in Financially Distressed Firms
Authors: EISDORFER ASSAF
Published: April 2008

This paper provides evidence of risk‐shifting behavior in the investment decisions of financially distressed firms. Using a real options framework, I show that shareholders' risk‐shifting incentives can reverse the expected negative relation between volatility and investment. I test two hypotheses that are consistent with risk‐shifting behavior: (i) volatility has a positive effect on distressed firms' investment; (ii) investments of distressed firms generate less value during times of high uncertainty. Empirical evidence using 40 years of data supports both hypotheses. I further evaluate the effect of various firm characteristics on risk shifting, and estimate the costs of the investment distortion.
Information Sales and Insider Trading with Long‐Lived Information
Authors: CESPA GIOVANNI
Published: April 2008

Fundamental information resembles in many respects a durable good. Hence, the effects of its incorporation into stock prices depend on who is the agent controlling its flow. Like a durable goods monopolist, a monopolistic analyst selling information intertemporally competes against herself. This forces her to partially relinquish control over the information flow to traders. Conversely, an insider solves the intertemporal competition problem through vertical integration, thus exerting tighter control over the information flow. Comparing market patterns I show that a dynamic market where information is provided by an analyst is thicker and more informative than one where an insider trades.
The Industry Life Cycle, Acquisitions and Investment: Does Firm Organization Matter?
Authors: MAKSIMOVIC VOJISLAV , PHILLIPS GORDON
Published: April 2008

We examine the effect of industry life‐cycle stages on within‐industry acquisitions and capital expenditures by conglomerates and single‐segment firms controlling for endogeneity of organizational form. We find greater differences in acquisitions than in capital expenditures, which are similar across organizational types. In particular, 36% of the growth recorded by conglomerate segments in growth industries comes from acquisitions, versus 9% for single‐segment firms. In growth industries, the effect of financial dependence on acquisitions and plant openings is mitigated for conglomerate firms. Plants acquired by conglomerate firms increase in productivity. The results suggest that organizational forms' comparative advantages differ across industry conditions.
Capital Gains Taxes and Asset Prices: Capitalization or Lock‐in?
Authors: DAI ZHONGLAN , MAYDEW EDWARD , SHACKELFORD DOUGLAS A. , ZHANG HAROLD H.
Published: April 2008

This paper demonstrates that the equilibrium impact of capital gains taxes reflects both the capitalization effect (i.e., capital gains taxes decrease demand) and the lock‐in effect (i.e., capital gains taxes decrease supply). Depending on time periods and stock characteristics, either effect may dominate. Using the Taxpayer Relief Act of 1997 as our event, we find evidence supporting a dominant capitalization effect in the week following news that sharply increased the probability of a reduction in the capital gains tax rate and a dominant lock‐in effect in the week after the rate reduction became effective.
The Term Structure of Real Rates and Expected Inflation
Authors: ANG ANDREW , BEKAERT GEERT , WEI MIN
Published: April 2008

Changes in nominal interest rates must be due to either movements in real interest rates, expected inflation, or the inflation risk premium. We develop a term structure model with regime switches, time‐varying prices of risk, and inflation to identify these components of the nominal yield curve. We find that the unconditional real rate curve in the United States is fairly flat around 1.3%. In one real rate regime, the real term structure is steeply downward sloping. An inflation risk premium that increases with maturity fully accounts for the generally upward sloping nominal term structure.
Share Issuance and Cross‐sectional Returns
Authors: PONTIFF JEFFREY , WOODGATE ARTEMIZA
Published: April 2008

Post‐1970, share issuance exhibits a strong cross‐sectional ability to predict stock returns. This predictive ability is more statistically significant than the individual predictive ability of size, book‐to‐market, or momentum. Our finding is related to research that finds that long‐run returns are associated with share repurchase announcements, seasoned equity offerings, and stock mergers, although our results remain strong even after exclusion of the data used in these studies. We estimate the issuance relation pre‐1970 and find no statistically significant predictive ability for most holding periods.
Pre‐Treatment of Si3N4 Filler Particles for the Improvement of Si3N4filler/Si–C–Nmatrix Particulate‐Reinforced Composites
Authors: Lee Sea‐Hoon
Published: April 2008

The surface of Si3N4 filler particles was modified by heat treatments before the onset of the precursor impregnation and pyrolysis process. The strength, Young's modulus, and hardness of Si3N4filler/Si–C–Nmatrix particulate‐reinforced composites (PRC) were improved up to 50%, 60%, and 71%, respectively, by the treatment. Si was formed at the surface of the Si3N4 filler particles by the treatment, which induced a strong bonding between the filler and the Si–C–N matrix during pyrolysis by a carbothermal reaction, thus improving the properties of the PRC.
Effect of Sintering Conditions and Microstructure on the Magnetostrictive Properties of Cobalt Ferrite
Authors: Bhame Shekhar D. , Joy Pattayil A.
Published: April 2008

The effects of sintering temperature and dwell time on the magnetostrictive properties of polycrystalline cobalt ferrite synthesized by the conventional ceramic method have been investigated. The present study showed that the magnitude of magnetostriction strongly depends on the microstructure of the final sintered product. The presence of small and uniform grains with less porous structure in the sintered material leads to enhancement of the magnetostrictive strain. Higher magnetostriction is obtained for samples sintered at a relatively lower temperature of 1100°C. These results are further corroborated by analyzing the effect of some additives during sintering on the microstructural and magnetostrictive properties.
Spatial Characterization of Piezoelectric Materials Using the Scanning Laser Intensity Modulation Method (LIMM)
Authors: Stewart Mark , Cain Markys
Published: April 2008

A novel system for characterizing the spatial variation of piezoelectric properties of piezoelectric ceramic samples has been developed and tested in a series of case studies. The system has been shown to be capable of detecting various types of defects in PZT ceramic materials including localized sample depoling brought about through thermal and mechanical treatments. It has also been used to detect defects due to environmental degradation under high dc bias. The present system can be used as an R&D tool, but with further developments to increase the scanning speed the technique could be extended for use in a Quality Assurance environment.
The effect of direct and indirect defenses in two wild brassicaceous plant species on a specialist herbivore and its gregarious endoparasitoid
Authors: Gols Rieta , Witjes Leontien M. A. , Van Loon Joop J. A. , Posthumus Maarten A. , Dicke Marcel , Harvey Jeffrey A.
Published: April 2008

Most studies on plant defenses against insect herbivores investigate direct and indirect plant defenses independently. However, these defenses are not necessarily mutually exclusive. Plant metabolites can be transmitted through the food chain and can also affect the herbivore's natural enemies. A conflict may arise when a natural enemy is attracted to a plant that is suboptimal in terms of its own fitness. In addition, plant defenses are often studied in cultivated plant species in which artificial selection may have resulted in reduced resistance against insect herbivores. In this study, we investigated both direct and indirect plant defenses in two closely related wild brassicaceous plant species, Brassica nigra L. and Sinapis arvensis L. The herbivore Pieris brassicae L. (Lepidoptera: Pieridae), which is specialized on brassicaceous plant species, developed faster and attained higher pupal mass when reared on B. nigra than on S. arvensis. In contrast, Cotesia glomerata L. (Hymenoptera: Braconidae), which is a gregarious endoparasitoid of P. brassicae caterpillars, developed equally well on P. brassicae irrespective of the food plant on which its host had been reared. The feeding strategy of the parasitoid larvae, that is, selectively feeding on hemolymph and fat body, is likely to allow for a much wider host‐size range without affecting the size or development time of the emerging parasitoids. In flight chamber experiments, C. glomerata, which had an oviposition experience in a host that fed on Brussels sprout, exhibited significant preference for host‐damaged B. nigra over host‐damaged S. arvensis plants. Headspace analysis revealed quantitative and qualitative differences in volatile emissions between the two plant species. This parasitoid species may use a range of cues associated with the host and the host's food plant in order to recognize the different plant species on which the host can feed. These results show that there is no conflict between direct and indirect plant defenses for this plant–host–parasitoid complex.
Implant Treatment of Patients with Edentulous Jaws: A 20‐Year Follow‐Up
Authors: Åstrand Per , Ahlqvist Jan , Gunne Johan , Nilson Hans
Published: April 2008

Background: Implant‐supported prostheses are today often used in rehabilitation of partially or totally edentulous patients. Both patients and the dental profession often regard implant treatment as successful in a life perspective. Therefore, studies with a long‐term follow‐up are important.

Purpose: The aim was to investigate the outcome of implant treatment with fixed prostheses in edentulous jaws after 20 years, with special reference to survival rate of implants and prostheses and frequency of peri‐implantitis.

Materials and Methods: The patient material was a group of patients treated in the early 1980s. The original patient group comprised the first 48 consecutive patients treated with implant‐supported prostheses at Umeå University. All patients were edentulous in one or two jaws. The patients had a mean age at the implant insertion of 54.3 years (range 40–74). At the planning of this study 20 years after treatment, 19 of the 48 patients were found to be deceased. Of the 29 patients still alive, 21 patients with altogether 23 implant‐supported prostheses could be examined clinically and radiographically. All patients were treated ad modum Brånemark® (Nobel Biocare AB, Göteborg, Sweden) with a two‐stage surgical procedure. The implants had a turned surface. Abutment connections were performed 3 to 4 months after fixture insertion in the mandible, and after a minimum of 6 months in the maxilla. The prostheses were fabricated with a framework of gold alloy and acrylic artificial teeth.

Results: The 21 patients (with 23 implant prostheses) examined had at the time of treatment got 123 implants (27 in the upper jaw and 96 in the lower jaw) inserted. Only one of these implants had been lost (about 2 years after loading) giving a survival rate of 99.2%. Very small changes occurred in the marginal bone level. Between the 1 and 20‐year examinations, the mean bone loss was 0.53 mm and the mean bone level at the final examination was 2.33 mm below the reference point.

Conclusions: This follow‐up over two decades of implant‐supported prostheses demonstrates a very good prognosis for the treatment performed. The frequencies of peri‐implantitis, implant failures, or other complications were very small, and the original treatment concept with a two‐stage surgery and a turned surface of the implants will obviously give very good results.
Clinical and Microbiological Determinants of Ailing Dental Implants
Authors: Tabanella Giorgio , Nowzari Hessam , Slots Jorgen
Published: April 2008

Background: The failure of the host tissue to establish or maintain osseointegration around dental implants is due to either occlusal or parafunctional forces, premature loading, ill‐directed stress, or microbial infection. The long‐term failure rate of dental implants is generally 5–10%. Although a variety of etiologies of early peri‐implant bone loss (from implant placement to 1‐year post‐loading) have been proposed, factors associated with late implant failures are less well understood but are probably related to both the peri‐implant microbial environment and host factors. Discriminating between causes of implant failure is of importance for instituting a successful implant therapy.

Purpose: The objective of this cross‐sectional split‐mouth study was to identify clinical, radiographic, and bacterial characteristics of peri‐implant disease sites.

Materials and Methods: Fifteen patients with bilateral implants (Brånemark®, Nobel Biocare AB, Göteborg, Sweden; and 3i™ implant systems, Implant Innovations Inc., Palm Beach Gardens, FL, USA) participated in the study. Sites with peri‐implantitis (radiographic bone loss beyond the third implant thread) and peri‐implant healthy tissues (radiographic bone level above the first implant thread) were identified in periapical radiographs using a long‐cone paralleling projection technique. Microbiological identification was carried out using established anaerobic culture techniques. A descriptive statistics based on means and standard deviations was reported.

Results: Peri‐implant bone loss was associated with the absence of radiographic crestal lamina dura, peri‐implant pocket depth, pain on chewing, and the submucosal presence of the putative periodontopathogens Tannerella forsythia, Campylobacter species, and Peptostreptococcus micros. Pain was associated with P. micros, Fusobacterium species, and Eubacterium species.

Discussion and Conclusion: The absence of radiographic crestal lamina dura and the presence of suspected major periodontal pathogens seem to be associated to peri‐implantitis.
Effect of Hydroxyapatite and Titania Nanostructures on Early In Vivo Bone Response
Authors: Meirelles Luiz , Melin Lory , Peltola Timo , Kjellin Per , Kangasniemi Ilkka , Currie Fredrik , Andersson Martin , Albrektsson Tomas , Wennerberg Ann
Published: April 2008

Purpose: Hydroxyapatite (HA) or titania nanostructures were applied on smooth titanium implant cylinders. The aim was to investigate whether nano‐HA may result in enhanced osseointegration compared to nano‐titania structures.

Materials and Methods: Surface topography evaluation included detailed characterization of nano‐size structures present at the implant surface combined with surface roughness parameters at the micro‐ and nanometer level of resolution. Microstructures were removed from the surface to ensure that bone response observed was dependent only on the nanotopography and/or chemistry of the surface. Early in vivo histological analyses of the bone response (4 weeks) were investigated in a rabbit model.

Results: In the present study, nano‐titania‐coated implants showed an increased coverage area and feature density, forming a homogenous layer compared to nano‐HA implants. Bone contact values of the nano‐titania implants showed a tendency to have a higher percentage as compared to the nano‐HA implants (p = .1).

Conclusion: Thus, no evidence of enhanced bone formation to nano‐HA‐modified implants was observed compared to nano‐titania‐modified implants. The presence of specific nanostructures dependent on the surface modification exhibiting different size and distribution did modulate in vivo bone response.