bluuebunny/crossref_metadata_2025 huggingface dataset:
Cellular conditioning with trichostatin A enhances the anti‐stress response through up‐regulation of HDAC4 and down‐regulation of the IGF/Akt pathway
Authors: Chu Fei , Chou Pauline , Mirkin Bernard L. , Mousa Shaker A. , Rebbaa Abdelhadi
Published: May 2008

Evidence is accumulating that chromatin plays a major role in the control of cellular response to stress. This is best illustrated by the recent findings that chromatin‐modifying factors of class III histone deacetylases (sirtuins) are capable of protecting cells from oxidative and genotoxic stress. In particular, Sirt1 has been shown to mimic the action of caloric restriction for the prevention of aging‐associated diseases. In the present study, we have investigated the potential role of class I and II histone deacetylases (HDACs) in cellular protection against various stresses, including those caused by nutrient deprivation. For this, we utilized a cellular model in which expression of class I and II HDACs was altered as a result of cellular adaptation to trichostatin A (TSA), a selective inhibitor of these deacetylases. Our results indicated that TSA‐resistant cells also developed resistance to H2O2, DNA‐damaging agents, and to nutrient deprivation. Interestingly, the insulin signaling pathway mediated by Akt was inhibited in the TSA‐resistant cells, mirroring the effect of glucose deprivation on this pathway. Since expression of HDAC4 was consistently enhanced in the TSA‐resistant cell lines, we suggest that this enzyme may contribute to their anti‐stress response. In agreement with this, siRNA‐mediated knockdown of HDAC4 in stress‐resistant cells enhanced their sensitivity to the DNA‐damaging drug doxorubicin and also to glucose deprivation. Akt phosphorylation was also up‐regulated in response to HDC4 knockdown. Together, these findings suggest that cellular conditioning with TSA may represent a useful approach to mimic the effects of caloric restriction.
Stem Cell Review Series: Regulating highly potent stem cells in aging: environmental influences on plasticity
Authors: Edelberg Jay M. , Ballard Victoria L. T.
Published: May 2008

Significant advances in the past decade have revealed that a large number of highly plastic stem cells are maintained in humans through adulthood and are present even in older adults. These findings are notable in light of the reduced capacity for repair and regeneration in older tissues. The apparent dichotomy can be reconciled through an appreciation of the age‐associated changes in the microenvironmental pathways that govern adult stem cell plasticity and differentiation patterns. Specifically, the recent identification of the age‐related loss of the local platelet‐derived growth factor signals that promote the induction of cardiac myocytes from Oct‐3/4+ bone marrow stem cells, rather than impairment in the stem cells themselves, provides a template for understanding and targeting the environmental pathways underlying the regenerative capacity of older tissues and organs. It is projected that this paradigm extends to the overall regulation of adult stem cell biology, shifting the balance from tissue generation during development and maturation to the prevention of untoward stem cell differentiation with aging.
Institutional change and stability in postcommunist countries, 1990–2002
Authors: ARMINGEON KLAUS , CAREJA ROMANA
Published: May 2008

Abstract.  This article deals with the institutional change of 27 political systems in postcommunist countries, 1990–2002. The authors show that institutional change after the institutionalization of the postcommunist regime is limited and lock‐in effects are strong. This applies to the more democratic and affluent countries as well as to the more authoritarian regimes. The authors do not find evidence for theories of institutional change that see institutional development as a linear function of socio‐economic factors such as affluence or of domestic political power distribution. The European Union and NATO have an effect that is limited to the overall democratic character of the system.
Management of Multivessel Coronary Disease: Let Us Not Shortchange Drug‐Eluting Stents
Authors: HARJAI KISHORE J. , GRINES CINDY L.
Published: May 2008

A recent observational study of coronary artery graft (CABG) versus drug‐eluting stents (DES) performed in the state of New York reported that CABG was superior to DES for multivessel disease. Our comment provides rational criticism of this study, reviews the data that support a role for DES in the management of multivessel coronary disease, and emphasizes the need for ongoing prospective clinical trials in this area. Till randomized trial data become available, physicians should continue to use their clinical judgment based on existing evidence in managing their patients with multivessel coronary artery disease (CAD).
Race, Ethnicity, and Racism in Medical Anthropology, 1977–2002
Authors: Gravlee Clarence C. , Sweet Elizabeth
Published: May 2008

Researchers across the health sciences are engaged in a vigorous debate over the role that the concepts of “race” and “ethnicity” play in health research and clinical practice. Here we contribute to that debate by examining how the concepts of race, ethnicity, and racism are used in medical–anthropological research. We present a content analysis of Medical Anthropology and Medical Anthropology Quarterly, based on a systematic random sample of empirical research articles (n =283) published in these journals from 1977 to 2002. We identify both differences and similarities in the use of race, ethnicity, and racism concepts in medical anthropology and neighboring disciplines, and we offer recommendations for ways that medical anthropologists can contribute to the broader debate over racial and ethnic inequalities in health.
Dying under the Bird's Shadow: Narrative Representations ofDegedegeand Child Survival among the Zaramo of Tanzania
Authors: Kamat Vinay R.
Published: May 2008

In this article, I examine the cultural interpretations of degedege, an indigenous illness commonly recognized by the Zaramo people of coastal Tanzania as life threatening. Drawing on the narratives of three bereaved parents who lost a child to degedege, I analyze the contextual and circumstantial factors involved in these parents' negotiation of the identity of an illness and in their subsequent therapy seeking behavior. I show that even though cultural knowledge and etiological beliefs about degedege may be shared locally, there is significant variation in the therapeutic pathways that parents follow to deal with an actual episode of the illness. I emphasize the need for more contextualized data on health‐seeking behaviors, and argue that it is necessary to pay attention to the micropolitics of health care decision making at the household level. Finally, I also call attention to the politics of provider–patient communication at public health facilities as a means to improve public health interventions to increase child survival.
The Life and Death of a Street Boy in East Africa: Everyday Violence in the Time of AIDS
Authors: Lockhart Chris
Published: May 2008

This article focuses on the life history of a single street boy in northwestern Tanzania, whom I name Juma. I suggest that Juma's experiences and the life trajectory of himself and of significant individuals around him (particularly his mother) were structured by everyday violence. I describe everyday violence in terms of a conjuncture between macrostructural forces in East Africa (including a history of failed development schemes and the contemporary political economy of neoliberalism) and the lived experience of individuals as they negotiate local, contextual factors (including land‐tenure practices, the power dynamics between immediate and extended kin, life on the streets, and constructions of gender and sexuality). I suggest that AIDS and its many impacts on Juma's life course can only be understood in a broader context of everyday violence. From this basis, I draw several general conclusions regarding AIDS prevention and intervention strategies.
Effect of Incorporation of Cylindrical Inhomogeneities on the Strength Distributions of Brittle Materials
Authors: Tandon Rajan
Published: May 2008

Cylindrical inhomogeneities are often deliberately incorporated into engineering ceramics (e.g., fibers, vias, electrical feedthroughs). The thermal expansion mismatch between the matrix and inhomogeneity creates a state of localized stress. We show that for radial cracks around such inhomogeneities, there may be conditions of crack stability even in the presence of an external, destabilizing field. This stability, and the nature of the stress intensity factor due to local stresses, modifies the strength distribution of the matrix. A fracture‐mechanics approach allows the prediction of the new strength distributions. As an illustration of this approach, calculations for commonly used ceramic–metal inhomogeneity material pairs are discussed. Depending on the inhomogeneity/flaw size ratio, the new strength distributions can have lower or higher strength variability than the matrix. If the inhomogeneity radius (R) is chosen such that a majority of the cracks in the matrix are >0.25R, the material will have the highest possible strength and reduced variability.
A Y‐chromosome STR Marker Should Be Added to Commercial Multiplex STR Kits
Authors: Oz Carla , Zaken Neomi , Amiel Merav , Zamir Ashira
Published: May 2008

Abstract:  Autosomal short tandem repeat (STR) analysis has become highly relevant in the identification of victims from mass disasters and terrorist attacks. In such events, gender misidentification can be of grave consequences, yet the list reporting amelogenin amplification failure using STR multiplex kits continues to grow. Presented here are three such examples. In the first case, we present two male suspects who demonstrated amelogenin Y‐deficient results using two commercial kit procedures. The presence of their Y chromosomes was proven by obtaining a Y‐haplotype. The second case demonstrated a profile from a third male suspect where only the Y homolog of the XY pair was amplified. In events such as mass disasters or terrorist attacks, timely and reliable high throughput DNA typing results are essential. As the number of reported cases of amplification failure at the amelogenin gene continues to grow, we suggest that the incorporation of a better gender identification tool in commercial kits is crucial.
Throat‐Cutting of Accidental Origin
Authors: Demirci Serafettin , Dogan Kamil Hakan , Gunaydin Gursel
Published: May 2008

Abstract:  Incised wounds of the neck can be accidental, homicidal, or suicidal. In this paper, a death case has been presented where a spinning circular saw of a cutting machine in a workshop came off its place and cut the throat of a 30‐year‐old male who was operating the machine. There was an incision (15 cm × 5 cm) that began in the middle of the neck down the thyroid cartilage, extended horizontally to the left of the neck and ended on the outer part of the neck in the outer left side of m. trapezius. Death occurred because of exsanguination caused by the cutting of carotis artery and jugular vein. In the case we presented, although the cut in the neck initially suggested homicide, it was found to have occurred as a result of an accident after the autopsy and death scene investigation.
Kumho,Daubert, and the Nature of Scientific Inquiry: Implications for Forensic Anthropology*
Authors: Grivas Christopher R. , Komar Debra A.
Published: May 2008

Abstract: In the last 15 years, the US Supreme Court has implemented major changes concerning the admittance of expert testimony. In 1993,Daubert v. Merrell Dow Pharmaceuticalssuperseded theFryeruling in federal courts and established judges, not the scientific community, as the gatekeepers regarding the credibility of scientific evidence. In 1999, a lesser‐known but equally important decision,Kumho Tire v. Carmichael, ruled that technical expert testimony needed to employ the same rigor as outlined inDaubert, but experts can develop theories based on observations and apply such theories to the case before the court. Anthropology has never been defined as a hard science. Yet, many recent publications have modified existing techniques to meet theDaubertcriteria, while none have discussed the significance ofKumhoto anthropological testimony. This paper examines the impact ofDaubertandKumhoon forensic anthropology and illustrates areas of anthropological testimony best admitted underKumho’sguidance.
Endogenous institutional innovation and agroindustrialization on the Peruvian coast
Authors: Escobal Javier , Agreda Victor , Reardon Thomas
Published: May 2008

This paper presents an analysis of endogenous institutional innovations that have recently emerged in the agroindustrial zone of Chincha, on the coast of Peru. These innovations include: (1) contracts between agroindustrial firms and large farmers, introduced by the firms themselves to assure timely delivery and compliance with strict requirements implied by the emerging demanding quality and safety standards for agro‐export of processed asparagus; (2) management services exchanged for labor supervision and land collateral in share tenancy contracts between a management company and “farmer companies” of small cotton farmers. These contracts introduced by the management company illustrate those described theoretically by Eswaran and Kotwal [Am. Econ. Rev. 75 (3), 352–367]. The nature and importance of these institutional changes are twofold: (1) They were induced institutional innovations driven by the requirements of agroindustrialization itself. (2) Together they had ambiguous employment and income impacts (tending to the negative). On the one hand, the emergence of asparagus and firm‐farm contracts reduced employment through exclusion of small farms and shifts to capital‐intensive crops. On the other hand, the reinforcement of smallholder cotton and the emergence of farmer companies increased employment and income of smallholders. The institutional innovation allowed them to reduce risk and increase profits and thus access some of the benefits of agroindustrialization and globalization. While processing firm‐farm contracts are common in Peru, as is the presence of NGOs bringing subsidized credit, the private management firm innovation is rare and new in Peru and apparently also in the region, and of great interest. In fact, policymakers and NGOs have recently discovered that this innovation is taking place and are asking hard questions about whether this innovation can and will be diffused. The interest in the private for‐profit institutional change is sharpened by growing doubts about how economically sustainable and widespread a response NGO help can be to small farmers in maintaining their participation in income‐enhancing agroindustrialization. Moreover, with changes in land laws and markets the fluidity of the situation is apparent, with agroindustrial firms even starting to ask themselves whether contracts with large farms are necessary and best.
Agroindustrialization through institutional innovation Transaction costs, cooperatives and milk‐market development in the east‐African highlands
Authors: Holloway Garth , Nicholson Charles , Delgado Chris , Staal Steve , Ehui Simeon
Published: May 2008

Some small‐holders are able to generate reliable and substantial income flows through small‐scale dairy production for the local market; for others, a set of unique transaction costs hinders participation. Cooperative selling institutions are potential catalysts for mitigating these costs, stimulating entry into the market, and promoting growth in rural communities. Trends in cooperative organization in east‐African dairy are evaluated. Empirical work focuses on alternative techniques for effecting participation among a representative sample of peri‐urban milk producers in the Ethiopian highlands. The variables considered are a modern production practice (cross‐bred cow use), a traditional production practice (indigenous‐cow use), three intellectual‐capital‐forming variables (experience, education, and extension), and the provision of infrastructure (as measured by time to transport milk to market). A Tobit analysis of marketable surplus generates precise estimates of non‐participants' ‘distances’ to market and their reservation levels of the covariates — measures of the inputs necessary to sustain and enhance the market. Policy implications focus on the availability of cross‐bred stock and the level of market infrastructure, both of which have marked effects on participation, the velocity of transactions in the local community and, inevitably, the social returns to agroindustrialization.
The impact of the tomato agroindustry on the rural poor in Mexico
Authors: Barron María Antonieta , Rello Fernando
Published: May 2008

This article addresses the issue of whether the tomato agroindustry (TAI) has been an effective instrument in the reduction of rural poverty. The TAI is by far the most important agroindustry in Mexico in terms of exports and employment creation. Most of the laborers employed by the TAI in northwest Mexico are temporary migrants coming from poverty‐stricken regions in southern Mexico. Conditions of poverty‐induced migration are explained. The characteristics and strategies of large, modern tomato enterprises are analyzed. The main conclusion is that migrant income earned in the tomato fields and packing plants, is fundamental for the bare survival in villages in poverty‐stricken regions. However, this does not provide a solution to poverty alleviation because migrant income is not sufficient to contribute to capital formation in the migrating communities, or the to create the conditions for endogenous local development.
Links between economic liberalization and rural resource degradation in the developing regions
Authors: Barbier Edward B.
Published: May 2008

This paper examines evidence of the effects of economic liberalization and globalization on rural resource degradation in developing countries. The principal resource effects of concern are processes of land use change leading to forestland conversion, degradation and deforestation. The main trends in globalization of interest are trade liberalization and economy‐wide reforms in developing countries that have ‘opened up’ the agroindustrial sectors, thus increasing their export‐orientation. Such reforms have clearly spurred agroindustrialization, rural development and economic growth, but there is also concern that there may be direct and indirect impacts on rural resource degradation. The direct impacts may occur as increased agricultural activity leads to conversion of forests and increased land degradation from ‘unsustainable’ production methods. However, there may also be indirect effects if agroindustrial development displaces landless, near‐landless and rural poor generally, who then migrate to marginal agricultural lands and forest frontier regions. This paper explores these direct and indirect effects of globalization and agroindustrialization on rural resource degradation both generally, plus through examining case study evidence. The paper focuses in particular on the examples of structural adjustment, trade liberalization and agricultural development in Ghana, and maize sector liberalization in Mexico under North American Free Trade Agreement (NAFTA).
Représentations – observations sur Le tour du monde en quatre‐vingts jours
Authors: Färnlöf Hans
Published: May 2008

Dans Le tour du monde en quatre‐vingts jours (1873) sont développés trois types de représentations. Par la représentation générique, Verne inscrit sa variation « moderne » du roman d’aventures (Bakhtine) en modifiant l’enjeu de l’intrigue traditionnelle; par la représentation mimétique, il crée une dialectique efficace entre la didactique et le romanesque; par la représentation diégétique, il attribue différentes fonctions narratives à ses personnages principaux (Fogg et Passepartout). Ensemble, ces représentations témoignent d’une poétique conséquente et élaborée chez Verne, qui situe habilement son projet d’écriture et par rapport à l’héritage littéraire et par rapport à l’esthétique contemporaine. De ce fait, Verne occupe une place notable dans le champ littéraire de la deuxième moitié du XIXe siècle. Par conséquent, il conviendrait, dans le discours théorique et historique littéraires, de ne plus considérer systématiquement Verne comme simple « auteur populaire », mais de lui accorder la place qui correspond à sa juste valeur d’écrivain.
Heinrich der Teichner: Commentator and Critic of the Worlds of the Court and the Aristocracy
Authors: Classen Albrecht
Published: May 2008

In the late Middle Ages poets increasingly voiced severe criticism of the social conditions of their time; they especially targeted the world of the courts and aristocracy at large. One of the most outspoken representatives of this criticism was the fourteenth‐century Austrian poet Heinrich der Teichner, heretofore fairly little studied and even less known among the reading public today. He certainly relied on the traditional topos of court criticism that can be traced back at least to the twelfth and eleventh centuries, but his comments about the courts and the nobility are extremely biting and explicit. This article identifies some of the key passages in Teichner’s voluminous poetic oeuvre in which he offers poignant social, moral, and political commentary about the shortcomings of his time. Teichner can be counted among the leading voices of his time particularly because of his unabashed and outspoken discussion of fundamental shortcomings among the upper level of late medieval society.1
Clinician observation of physiological trend monitoring to identify late‐onset sepsis in preterm infants
Authors: Dewhurst Christopher J , Cooke Richard WI , Turner Mark A
Published: May 2008

Aim: To determine whether trends in routinely collected physiological variables can be used retrospectively to classify infants according to the presence or absence of late‐onset neonatal sepsis.

Methods: Case control study. Thirty infants born ≤32 weeks of gestation who developed late‐onset sepsis were matched with 30 controls for gestational and postnatal age but remained sepsis free. For each infant, 25 clinicians inspected 48 h of routine monitoring of heart rate, respiratory rate and oxygen saturation. Clinicians were asked to determine whether the recording was obtained from an infant who did or did not develop sepsis and also indicate how confident they were in their judgement. Clinicians were stratified into three groups by professional role.

Results: The median correct assignment of infant's recordings was 67% (IQR 62–72). When very confident, this improved to 82% (IQR 67–88). Overall sensitivity was 53% (IQR 43–63) and specificity 80% (IQR 67–87). Advanced neonatal nurse practitioners consistently assigned babies to the correct group more often than other professional groups.

Conclusion: The simple observation physiological trend graphs can classify infants according to the presence or absence of late‐onset neonatal sepsis. The accuracy of this method is good to strong but varies with experience of neonatal intensive care.
Activities in daily living and schoolwork task performance in children with complex congenital heart disease
Authors: Granberg Marie , Rydberg Annika , Fisher Anne G
Published: May 2008

Aim: To examine if children with complex congenital heart disease (CHD) differ significantly from healthy children in performance of activities in daily living (ADL) and schoolwork tasks.

Methods: Fourteen children with complex CHD (3–14 years) were matched in pairs by age and gender to healthy children (n = 14). The ADL Taxonomy was used to evaluate ability to perform ADL and the School Version of the Assessment of Motor and Process Skills (AMPS) to evaluate quality of schoolwork task performance.

Results: The children with complex CHD had significantly lower mean ADL, school motor and school process performance. Eight of the pairs differed significantly in school motor ability, ten in school process performance and nine in ability to perform ADL.

Conclusion: This study indicates that there is a difference in overall performance both in ADL and schoolwork task performance between children with complex CHD and healthy children. These findings may suggest that early interventions should be provided for children with complex CHD, who often do not receive such services, in order to enhance participation in childhood ADL and schoolwork.
IgA endomysium antibodies – an early predictor for celiac disease in children without villous atrophy
Authors: Grodzinsky E , Fälth‐Magnusson K , Högberg L , Jansson G , Laurin P , Stenhammar L
Published: May 2008

Aim: To evaluate possible differences between children with anti‐endomysium antibodies (EMA) positivity and normal small bowel mucosa and children with positive EMA and an enteropathy diagnosed as celiac disease (CD).

Methods: Children with suspected CD and positive EMA (≥1/10) undergoing small bowel biopsy during 1996 to 2002, were investigated (n = 133). Data registered were: year and month of birth, timing of the first biopsy, sex, heredity for CD, dermatitis herpetiformis and diabetes mellitus and outcome of the anti‐gliadin antibody test (AGA). The case group, with EMA positivity and normal histology (n = 39; 59% female, mean age at the first biopsy 7.3 years, range 1.4–16), was compared with the disease control group, with positive EMA and a biopsy suggestive and further on diagnosed as CD (n = 94; 56% female; mean age 7.6 years at the first biopsy, range 0.70–17).

Results: AGA positivity and heredity for CD were found to predict the outcome of a pathological jejunal mucosa. Nineteen of the 39 children in the case group were rebiopsied of whom 11 had developed an enteropathy during a follow‐up period of 2–7 years (median 4.5 years).

Conclusions: EMA positivity in the absence of small bowel enteropathy could be a very early predictor for later overt CD, and necessitates further follow‐up, especially if the child is AGA positive and there is a family history of CD.
Emotional Returns and Emotional Costs in Privately Held Family Businesses: Advancing Traditional Business Valuation
Authors: Astrachan Joseph H. , Jaskiewicz Peter
Published: May 2008

This article introduces a formula to assess the total value of privately held family businesses from the owner's perspective. It is argued that the total value of a business is not only composed of its financial worth and private benefits, as is usually assumed by traditional financial theory, but that emotional components also have an impact on valuation. In particular, it is assumed that emotional returns (ER) positively affect total value, whereas emotional costs (EC) negatively affect total value. Even though every stakeholder faces emotional costs and returns, it is solely the family business owner who ultimately decides on the worth of a business and consequently factors ER-EC into his or her valuation. The presented formula provides a better understanding of investment decisions in family businesses and a more accurate valuation of these businesses.
Determinants of the Internationalization Pathways of Family Firms: An Examination of Family Influence
Authors: Graves Chris , Thomas Jill
Published: May 2008

Internationalization is recognized as a valuable strategy for organizations' growth and expansion; however, little is known about the internationalization behavior of family firms. Using stage model theory, the internationalization processes of eight family firms from their foundation to the present time are examined. Three key determinants of the internationalization pathways taken by family firms are identified: the level of commitment toward internationalization, the financial resources available, and the ability to commit and use those financial resources to develop the required capabilities. Furthermore, how the family unit influenced these determinants is explored. The implications for family business practitioners and ideas for future research are discussed.
A novel splice variant of occludin deleted in exon 9 and its role in cell apoptosis and invasion
Authors: Gu Jin‐Mo , Lim Seung Oe , Park Young Min , Jung Guhung
Published: May 2008

The tight junction protein occludin participates in cell adhesion and migration and has been shown to possess antitumorigenic properties; however, the exact mechanism underlying these effects is poorly understood. In liver cell lines, we identified an occludin splice variant deleted in exon 9 (OccΔE9). Furthermore, comparison analysis of wild‐type occludin (OccWT) and OccΔE9 revealed that exon 9 played important roles in the induction of mitochondria‐mediated apoptosis and the inhibition of invasion, along with the downregulation of matrix metalloproteinase expression. In addition, by using the calcium indicator X‐rhod‐1, and the inositol trisphosphate receptor inhibitor 2‐aminoethoxydiphenyl borate, we found that OccWT but not OccΔE9 increased calcium release from the endoplasmic reticulum. In conclusion, our results showed that occludin mediates apoptosis and invasion by elevating the cytoplasmic calcium concentration and that exon 9 of occludin is an important region that mediates these effects.
Investigating the role of the invariant carboxylate residues E552 and E1197 in the catalytic activity of Abcb1a (mouse Mdr3)
Authors: Carrier Isabelle , Gros Philippe
Published: May 2008

The invariant carboxylate residue which follows the Walker B motif (hyd4DE/D) in the nucleotide‐binding domains (NBDs) of ATP‐binding cassette transporters is thought to be involved in the hydrolysis of the γ‐phosphate of MgATP, either by activating the attacking water molecule or by promoting substrate‐assisted catalysis. In Abcb1a, this invariant carboxylate residue corresponds to E552 in NBD1 and E1197 in NBD2. To further characterize the role of these residues in catalysis, we created in Abcb1a the single‐site mutants E552D, N and A in NBD1, and E1197D, N and A in NBD2, as well as the double‐mutant E552Q/E1197Q. In addition, we created mutants in which the Walker A K → R mutation known to abolish ATPase activity was introduced in the non‐mutant NBD of E552Q and E1197Q. ATPase activity, binding affinity and trapping properties were tested for each Abcb1a variant. The results suggest that the length of the invariant carboxylate residue is important for the catalytic activity, whereas the charge of the side chain is critical for full turnover to occur. Moreover, in the double‐mutants where the K → R mutation is introduced in the ‘wild‐type’ NBD of the E → Q mutants, single‐site turnover is observed, especially when NBD2 can undergo γ‐Pi cleavage. The results further support the idea that the NBDs are not symmetric and suggest that the invariant carboxylates are involved both in NBD–NBD communication and transition‐state formation through orientation of the linchpin residue.
The Impact of Performance Level Misclassification on the Accuracy and Precision of Percent at Performance Level Measures
Authors: Betebenner Damian W. , Shang Yi , Xiang Yun , Zhao Yan , Yue Xiaohui
Published: May 2008

No Child Left Behind (NCLB) performance mandates, embedded within state accountability systems, focus school AYP (adequate yearly progress) compliance squarely on the percentage of students at or above proficient. The singular importance of this quantity for decision‐making purposes has initiated extensive research into percent proficient as a measure of school quality. In particular, technical discussions have scrutinized the impact of sampling, measurement, and other sources of error on percent proficient statistics. In this article, we challenge the received orthodoxy that measurement error associated with individual students' scores is inconsequential for aggregate percent proficient statistics. Synthesizing current classification accuracy research with techniques from randomized response designs, we establish results which specify the extent to which measurement error—manifest as performance level misclassifications—produces bias and increases error variability for percent at performance level statistics. The results have direct relevance for the design of coherent and fair accountability systems based upon assessment outcomes.
False killer whales (Pseudorca crassidens) around the main Hawaiian Islands: Long‐term site fidelity, inter‐island movements, and association patterns
Authors: Baird Robin W. , Gorgone Antoinette M. , McSweeney Daniel J. , Webster Daniel L. , Salden Dan R. , Deakos Mark H. , Ligon Allan D. , Schorr Gregory S. , Barlow Jay , Mahaffy Sabre D.
Published: May 2008

Abstract

Despite their world‐wide distribution throughout the tropics and subtropics, false killer whales (Pseudorca crassidens) are one of the lesser‐known large odontocetes. Genetic evidence indicates a demographically isolated population around the main Hawaiian Islands. We examine site fidelity, movements and association patterns in this population using data from directed surveys and opportunistic photographs from 1986 to 2007. This species was only infrequently encountered, and while found in depths from 38 to 4,331 m, sighting rates were greatest in depths >3,000 m. We photo‐identified 152 distinctive individuals. Resighting rates were high, with an average of 76.8% of distinctive individuals within groups documented on more than one occasion. Most (86.6%) were linked by association into a single social network; only one large group (16 distinctive individuals), documented the farthest offshore (42–70 km), did not link by association to that large network, and may be part of an offshore population. Individual movements of up to 283 km were documented, with a large proportion of individuals moving among islands. Individuals were resighted up to 20.1 yr after first being documented, showing long‐term fidelity to the islands. Repeated associations among individuals were documented for up to 15 yr, and association analyses indicate preferred associations and strong bonds among individuals.
Validation of an Invertebrate Community Index for Urban Streams for an Alabama Coastal Plains Watershed1
Authors: Collins Christa L. , Mullen Michael W. , Stewart Paul M. , Cliff Webber E.
Published: May 2008

Abstract:  The purpose of this study was to validate the application of an invertebrate community index (ICI) to assess the biological integrity of urban streams. Validation involved comparing chemical and habitat data to ICI scores from 20 urban streams and four least‐impacted streams in the Choctawhatchee and Pea River watersheds located in Southeast Alabama. Chemical and habitat data were collected to support whether the ICI accurately predicts the health of the streams. A significant difference between urban and least‐impacted ICI scores, habitat evaluation scores, chemical variables, taxa richness, and Shannon‐Wiener diversity were observed when urban sites were compared with least‐impacted sites using Mann‐Whitney U‐test. Urban sites having low ICI scores, low species richness and diversity, and poor habitat showed greater impairment than least‐impacted sites. Cluster analysis of macroinvertebrate assemblages indicated two clusters. Significant differences between clusters in habitat evaluations, chemical parameters, and ICI scores showed that some urban sites were more degraded than other urban sites in the study. Differentiation between least‐impacted and urban sites indicated that the ICI provided valid biotic assessments. Therefore, this study validated that the ICI is capable of predicting the biological integrity of urban streams in the Choctawhatchee and Pea River watersheds.
Neural Network Input Selection for Hydrological Forecasting Affected by Snowmelt1
Authors: Parent Annie‐Claude , Anctil François , Cantin Véronique , Boucher Marie‐Amélie
Published: May 2008

Abstract:  Snowmelt largely affects runoff in watersheds in Nordic countries. Neural networks (NN) are particularly attractive for streamflow forecasting whereas they rely at least on daily streamflow and precipitation observations. The selection of pertinent model inputs is a major concern in NNs implementation. This study investigates performance of auxiliary NN inputs that allow short‐term streamflow forecasting without resorting to a deterministic snowmelt routine. A case study is presented for the Rivière des Anglais watershed (700 km2) located in Southern Québec, Canada. Streamflow (Q), precipitations (rain R and snow S, or total P), temperature (T) and snow lying (A) observations, combined with climatic and snowmelt proxy data, including snowmelt flow (QSM) obtained from a deterministic model, were tested. NN implemented with antecedent Q and R produced the largest gains in performance. Introducing increments of A and T to the NNs further improved the performance. Long‐term averages, seasonal data, and QSM failed to improve the networks.
Effects of Riparian Vegetation and Watershed Urbanization on Fishes in Streams of the Mid‐Atlantic Piedmont (USA)1
Authors: Horwitz Richard J. , Johnson Thomas E. , Overbeck Paul F. , O’Donnell T. Kevin , Hession W. Cully , Sweeney Bernard W.
Published: May 2008

Abstract: The joint influences of riparian vegetation and urbanization on fish assemblages were analyzed by depletion sampling in paired forested and nonforested reaches of 25 small streams along an urbanization gradient. Nonforested reaches were narrower than their forested counterparts, so densities based on surface area differ from linear densities (based on reach length). Linear densities (based on number or biomass of fish) of American eel, white sucker and tesselated darter, and the proportion of biomass of benthic invertivores were significantly higher in nonforested reaches, while linear densities of margined madtom and the number of pool species were significantly higher in forested reaches. Observed riparian effects may reflect differences in habitat and algal productivity between forested and nonforested reaches. These results suggest that relatively small‐scale riparian restoration projects can affect local geomorphology and the abundance of fish. Dense vegetative cover in riparian zones and similar or analogous habitats in both forested and nonforested reaches, the relatively small scale of the nonforested reaches, and the low statistical power to detect differences in abundance of rare species may have limited the observed differences between forested and nonforested reaches. There was a strong urbanization gradient, with reductions of intolerant species and increases of tolerant species and omnivores with increasing urbanization. Interactions between riparian vegetation type and urbanization were found for blacknose dace, creek chub, tesselated darter, and the proportion of biomass of lithophilic spawners. The study did not provide consistent support for the hypotheses that responses of fish to riparian vegetation would be overwhelmed by urban degradation or insignificant at low urbanization.
Factors Affecting Sediment Oxygen Demand Dynamics in Blackwater Streams of Georgia’s Coastal Plain1
Authors: Utley Barbra C. , Vellidis George , Lowrance Richard , Smith Matt C.
Published: May 2008

Abstract:  Sediment oxygen demand (SOD) is believed to be an important process affecting dissolved oxygen (DO) concentrations in blackwater streams of the southeastern coastal plain. Because very few data on SOD are available, it is common for modelers to take SOD values from the literature for use with DO models. In this study, SOD was measured in seven blackwater streams of the Suwannee River Basin within the Georgia coastal plain for between August 2004 and April 2005. SOD was measured using four in situ chambers and was found to vary on average between 0.1 and 2.3 g O2/m/day across the seven study sites throughout the study period. SOD was found to vary significantly between the watersheds within the Suwannee River Basin. However, land use was not found to be the driving force behind SOD values. Statistical analyses did find significant interaction between land use and watersheds suggesting that an intrinsically different factor in each of the watersheds may be affecting SOD and the low DO concentrations. Further research is needed to identify the factors driving SOD dynamics in the blackwater streams of Georgia’s coastal plain. Results from this study will be used by the Georgia Department of Natural Resources – Environmental Protection Division as model input data for the development and evaluation of DO total maximum daily loads in the Georgia coastal plain.
Nutrient and Sediment Production, Watershed Characteristics, and Land Use in the Tahoe Basin, California‐Nevada1
Authors: Coats Robert , Larsen Melissa , Heyvaert Alan , Thomas James , Luck Matthew , Reuter John
Published: May 2008

Abstract:  In efforts to control the degradation of water quality in Lake Tahoe, public agencies have monitored surface water discharge and concentrations of nitrogen, phosphorus, and suspended sediment in two separate sampling programs. The first program focuses on 20 watersheds varying in size from 162 to 14,000 ha, with continuous stream gaging and periodic sampling; the second focuses on small urbanized catchments, with automated sampling during runoff events. Using data from both programs, we addressed the questions (1) what are the fluxes and concentrations of nitrogen and phosphorus entering the lake from surface runoff; (2) how do the fluxes and concentrations vary in space and time; and (3) how are they related to land use and watershed characteristics? To answer these questions, we calculated discharge‐weighted average concentrations and annual fluxes and used multiple regression to relate those variable to a suite of GIS‐derived explanatory variables. The final selected regression models explain 47‐62% of the variance in constituent concentrations in the stormwater monitoring catchments, and 45‐72% of the variance in mean annual yields in the larger watersheds. The results emphasize the importance of impervious surface and residential density as factors in water quality degradation, and well‐developed soil as a factor in water quality maintenance.
Regional Scale Stressor‐Response Models in Aquatic Ecosystems1
Authors: Conrad Lamon E. , Qian Song S.
Published: May 2008

Abstract:  A systematic method for identification and estimation of regional scale stressor‐response models in aquatic ecosystems will be useful in monitoring and assessment of aquatic resources, determination of regional nutrient criteria and for increased understanding of the differences between regions. The model response variable is chlorophyll a, a measure of algal density, while the stressors include nutrient concentrations from the USEPA Nutrient Criteria Database (NCD) for lakes/ponds and reservoirs of the continental United States. The NCD has observations for both stressors and biological responses determined using methods that are not consistently available at the continental scale. To link multiple environmental stressors to biological responses and quantify uncertainty in model predictions, we take a multilevel modeling approach to the estimation of a linear model for prediction of log Chlorophyll a using predictors log TP and log TN. The multilevel modeling approach allows us to adjust the impact of covariates at all levels (observation, higher level groups) for the simultaneous operation of contextual and individual variability in the outcome. Here, we wish to allow separate regression coefficients for inference regarding similarities and differences between each of 14 ecoregions, and between the two water‐body types, lakes/ponds and reservoirs. We are also interested in the nuisance effects of the categorical variables indicating the type of nitrogen measurements (three levels) and the type of chlorophyll a measurements (four levels) used. Model‐based determination of nutrient criteria points to an apparent incompatibility of criteria developed for nutrient stressors and eutrophication responses using current Environmental Protection Agency’s guidance.
Isolation and characterization of microsatellite loci in the Malaysian giant freshwater prawn, Macrobrachium rosenbergii
Authors: BHASSU S. , SEE L. M. , HASSAN R. , SIRAJ S. S. , TAN S. G.
Published: May 2008

Eight single locus microsatellite markers were developed to characterize the Malaysian giant freshwater prawn, Macrobrachium rosenbergii. These microsatellites were isolated from an enriched genomic library contained by using a 5′‐anchored polymerase chain reaction technique. Primers were designed to flank the repeat sequences and subsequently used to characterize 30 unrelated individuals of the giant freshwater prawn. The polymerase chain reaction amplification products of these eight microsatellite loci were polymorphic with the number of alleles ranging from two to 10 alleles per locus while the levels of heterozygosity ranged from 0.6333 to 0.8667.
Favorable environments and the persistence of naturally rare species
Authors: Harrison Susan , Viers Joshua H. , Thorne James H. , Grace James B.
Published: May 2008

In an era of rapid climate change, it is important to understand how naturally rare species—such as those with small geographic ranges, specialized habitat requirements, and low local abundances—have persisted in time and space. In the flora we studied, species with all three forms of rarity inhabited geographic regions with more benign climates (higher total and summer rainfall, less extreme seasonal temperatures) and larger areas of their specialized habitat within 10 km than did more common species in the same habitats. Similar differences were also seen in congener‐only comparisons. We found no evidence for two nonexclusive alternatives, that naturally rare species had more extinction‐resistant life history traits, or that they belonged to more rapidly speciating taxa than common species. Understanding the association of rare species with benign environments may help in the design of effective conservation strategies for geographic regions of high diversity and endemism under changing climates. In particular, our findings highlight the extra climatic sensitivities of rare species with edaphic or other specialization, and how the needs of these species may be met by either refugia or translocation strategies.
Dog‐Associated Risk Factors for Human Plague
Authors: Hannah Gould L. , Pape J. , Ettestad P. , Griffith K. S. , Mead P. S.
Published: May 2008

Plague is a rare but often fatal zoonosis endemic to the western United States. Previous studies have identified contact with pets as a potential risk factor for infection. We conducted a matched case–control study to better define the risks associated with pets at both the household and individual levels. Using a written questionnaire, we surveyed nine surviving plague patients, 12 household members of these patients, and 30 age‐ and neighbourhood‐matched controls about household and individual exposures. Overall, 79% of households had at least one dog, 59% had at least one cat and 33% used flea control, with no significant differences between case and control households. Four (44%) case households reported having a sick dog versus no (0%) control households [matched odds ratio, (mOR) 18.5, 95% confidence interval (CI) 2.3–∞], and four (44%) patients reported sleeping in the same bed with a pet dog versus three (10%) controls (mOR 5.7, 95% CI 1.0–31.6). Within case households with multiple members, two (40%) of five patients slept with their dogs versus none (0%) of 12 healthy family members (P = 0.13). The exposures to cats were not significant. Sleeping in the same bed as a pet dog remained significantly associated with infection in a multivariate logistic regression model (P = 0.046). Our findings suggest that dogs may facilitate the transfer of fleas into the home and that activities with close extended contacts with dogs may increase the risk of plague infection.