bluuebunny/crossref_metadata_2025 huggingface dataset:
Endocrine signatures underlying plasticity in postembryonic development of a lower termite, Cryptotermes secundus (Kalotermitidae)
Authors: Korb Judith , Hoffmann Katharina , Hartfelder Klaus
Published: May 2009

SUMMARY
Wood‐dwelling termites are characterized by an extremely high and unique developmental flexibility that allows workers, which are immatures, to explore all caste options. The endocrine signatures underlying this flexibility are only vaguely understood. We determined juvenile hormone (JH) and ecdysteroid hemolymph titers during postembryonic development and in terminal instars of the drywood termite Cryptotermes secundus using field and laboratory colonies. Postembryonic development is characterized by a drop in JH titers at the transition from larval (individuals without wing buds) to nymphal (individuals with wing buds) instars. JH titers were low in winged sexuals and reproducing primary reproductives (<200 pg/μl) but were by an order of magnitude higher in neotenic replacement reproductives. The unique regressive molts of termites seem to be characterized by elevated JH titers, compared with progressive or stationary molts. Ecdysteroid titers were generally low in nymphal instars and in primary reproductives (<50 pg/μl). It was only during the third and fourth nymphal instars and in winged sexuals where some individuals showed elevated ecdysteroid titers. These results are the most comprehensive endocrinological data set available for any lower termite, with the potential to serve as baseline for understanding the extreme developmental flexibility underlying the evolution of social life in termites.
Development of a wingless morph in the ladybird beetle, Adalia bipunctata
Authors: Lommen Suzanne T. E. , Saenko Suzanne V. , Tomoyasu Yoshinori , Brakefield Paul M.
Published: May 2009

SUMMARY
Many taxa of winged insects have independently lost the ability to fly and often possess reduced wings. Species exhibiting natural variation in wing morphology provide opportunities to investigate the genetics and developmental processes underlying the evolution of alternative wing morphs. Although many wing dimorphic species of beetles are known, the underlying mechanisms of variation are not well understood in this insect order. Here, we examine wing development of wild type and natural wingless morphs of the two‐spot ladybird beetle, Adalia bipunctata. We show that both pairs of wings are distally truncated in the wingless adults. A laboratory population of the wingless morph displays heritable variation in the degree of wing truncation, reflecting reduced growth of the larval wing discs. The coexistence of variable wingless morphs supports the idea that typical monomorphic wingless insects may be the result of a gradual evolution of wing loss. Gene expression patterns in wing discs suggest that the conserved gene network controlling wing development in wild‐type Adalia is disrupted in the dorsoventral patterning pathway in the wingless morphs. Previous research on several species of ant has revealed that the anteroposterior wing patterning pathway is disrupted in wingless workers. Future investigations should confirm whether interruptions in both taxa are limited to the patterning pathways found thus far, or whether there are also shared interruption points. Nevertheless, our results highlight that diverse mechanisms of development are likely to underlie the evolution of wingless insects.
Speckled Lentiginous Nevus Syndrome Associated with Musculoskeletal Abnormalities
Authors: Ramolia Paras , Treadwell Patricia , Haggstrom Anita
Published: May 2009

Abstract:  Speckled lentiginous nevus syndrome is a recently described neurocutaneous disorder characterized by speckled lentiginous nevus in association with hyperhidrosis, skin dysesthesia, and muscular weakness in an ipsilateral manner. We report a 9‐year‐old boy with a large speckled lentiginous nevus on his trunk, bilateral upper extremities, and neck associated with hyperhidrosis and nonspecific pain in the distribution of the nevus in addition to prominent upper extremity asymmetry and scoliosis. Similar musculoskeletal abnormalities have been reported in patients with phacomatosis pigmentovascularis and phacomatosis pigmentokeratotica which feature speckled lentiginous nevus; however, this patient demonstrates striking musculoskeletal abnormalities in the absence of coexisting vascular lesions or nevus sebaceous.
Familial Auriculotemporal Nerve (Frey) Syndrome
Authors: Sethuraman Gomathy , Mancini Anthony J.
Published: May 2009

Abstract:  Auriculotemporal nerve (Frey) syndrome in children is rare, and may be misdiagnosed as food allergy. Trauma to the auriculotemporal nerve during forceps‐assisted delivery has been implicated in about half of the reported childhood Frey syndrome cases and most patients present with unilateral involvement. We describe two Caucasian sisters with bilateral Frey syndrome, neither of whom was delivered with forceps assistance, and highlight its distinction from food allergy. Frey syndrome may occur in a familial pattern, and in the absence of a history of perinatal trauma.
Plant and Soil Responses to Created Microtopography and Soil Treatments in Bottomland Hardwood Forest Restoration
Authors: Simmons Matthew E. , Ben Wu X. , Whisenant Steven G.
Published: May 2009

Although microtopographic heterogeneity is common in bottomland hardwood forests, it is rarely considered in bottomland restoration efforts. The objective of this study was to determine the responses of hydrologic condition, soil physiochemical properties, and introduced and colonizing vegetation to created microtopography and soil treatments at a landfill borrow pit in northern Texas. A series of mounds and pools were created and planted with fast‐growing pioneer species as well as more desirable, later‐successional species. Erosion control mats were installed on half the plots as a source of organic matter. Erosion control mats had little influence on introduced seedling survival or colonizing species abundance, but microtopography strongly influenced hydrologic condition, soil properties, seedling survival and growth, and colonizing species abundance and distribution. Pools were flooded during much of the summer months and had significantly higher nitrate and total nitrogen concentrations than mounds. Topographic position had little effect on survival of pioneer species, but mortality of most later‐successional species was highest in pools. Colonizing species distribution and abundance were also strongly related to topographic position. Despite differences in soil nutrient concentration among topographic zones, hydrologic condition likely had the strongest influence on growth and survival of planted species and distribution of colonizing species. Creating microtopography resulted in a spatially heterogeneous system that reflected variations in natural bottomlands, and introducing a mix of species (pioneer and later‐successional) across topographic and hydrologic gradients may improve the establishment and survival of a diverse community when hydrologic condition is highly variable or difficult to predict.
Eyelid myoclonia with absences (Jeavons syndrome): A well‐defined idiopathic generalized epilepsy syndrome or a spectrum of photosensitive conditions?
Authors: Striano Salvatore , Capovilla Giuseppe , Sofia Vito , Romeo Antonino , Rubboli Guido , Striano Pasquale , Trenité Dorothée Kasteleijn‐Nolst
Published: May 2009

Eyelid myoclonia with absences (EMA), or Jeavons syndrome, is a generalized epileptic condition clinically characterized by eyelid myoclonia (EM) with or without absences, eye closure‐induced electroencephalography (EEG) paroxysms, and photosensitivity; in addition, rare tonic–clonic seizures may also occur. Although first described in 1977 and widely reported by several authors within the last few years, EMA has not been yet recognized as a definite epileptic syndrome. However, when strict criteria are applied to the diagnosis, EMA appears to be a distinctive condition that could be considered a myoclonic epileptic syndrome, with myoclonia limited to the eyelids, rather than an epileptic syndrome with absences.
Idiopathic generalized epilepsy (IGE) syndromes in development: IGE with absences of early childhood, IGE with phantom absences, and perioral myoclonia with absences
Authors: Rubboli Guido , Gardella Elena , Capovilla Giuseppe
Published: May 2009

The classification of idiopathic generalized epilepsies (IGEs) is still controversial, with special reference to absence epilepsy syndromes. Strict, well‐defined criteria for syndromic definitions are necessary to delineate homogeneous conditions; however, this approach may leave a considerable group of patients unclassified, leading to the effort to categorize them in possible distinct subsyndromes. In this report, we review some of these possible IGE subsyndromes, such as IGE with absences of early childhood, IGE with phantom absences, and perioral myoclonia with absences, briefly commenting on the issues regarding their recognition as individual entities.
The autosomal recessively inherited progressive myoclonus epilepsies and their genes
Authors: Ramachandran Nivetha , Girard Jean‐Marie , Turnbull Julie , Minassian Berge A.
Published: May 2009

Autosomal recessively inherited progressive myoclonus epilepsies (PMEs) include Lafora disease, Unverricht‐Lundborg disease, the neuronal ceroid lipofuscinoses, type I sialidosis (cherry‐red spot myoclonus), action myoclonus–renal failure syndrome, and type III Gaucher disease. Almost all the autosomal recessively inherited PMEs are lysosomal diseases, with the exception of Lafora disease in which neither the accumulating material nor the gene products are in lysosomes. Progress in identifying the causative defects of PME is near‐complete. Much work lies ahead to resolve the pathobiology and neurophysiology of this group of devastating disorders.
Familial benign nonprogressive myoclonic epilepsies
Authors: Striano Pasquale , De Falco Fabrizio A. , Minetti Carlo , Zara Federico
Published: May 2009

Work on the classification of epileptic syndromes is ongoing, and many syndromes are still under discussion. In particular, special difficulty still persists in correctly classifying epilepsies with myoclonic seizures. The existence of special familial epileptic syndromes primarily showing myoclonic features has been recently suggested on the basis of a clear pattern of inheritance or on the identification of new chromosomal genetic loci linked to the disease. These forms in development include familial infantile myoclonic epilepsy (FIME), benign adult familial myoclonic epilepsy (BAFME), or autosomal dominant cortical myoclonus and epilepsy (ADCME), and, maybe, adult‐onset myoclonic epilepsy (AME). In the future, the identification of responsible genes and the protein products will contribute to our understanding of the molecular pathways of epileptogenesis and provide neurobiologic criteria for the classification of epilepsies, beyond the different phenotypic expression.
Myoclonic status in nonprogressive encephalopathies: An update
Authors: Elia Maurizio
Published: May 2009

Myoclonic status in nonprogressive encephalopathies (MSNE) is an epileptic syndrome in development, characterized by the early onset of continuous diffuse epileptiform abnormalities, accompanied by positive and/or negative phenomena correlated with transient and recurring motor, cognitive, or behavioral disturbances. Outcome of MSNE is poor and may determine progressive neurologic deterioration. MSNE is not easy to recognize and should be distinguished from progressive myoclonic epilepsies and other rarely reported infantile myoclonic epilepsies. The identification of MSNE may guide the diagnostic work‐up, suggesting the presence of a genetic defect, such as Angelman syndrome, hypoxic–ischemic encephalopathy, or brain malformation.
Lateral temporal lobe epilepsies: Clinical and genetic features
Authors: Michelucci Roberto , Pasini Elena , Nobile Carlo
Published: May 2009

Lateral temporal epilepsies are still a poorly studied group of conditions, covering lesional and nonlesional cases. Within nonlesional cases, autosomal dominant lateral temporal epilepsy (ADLTE) is a well‐defined, albeit rare, condition characterized by onset in adolescence or early adulthood of lateral temporal seizures with prominent auditory auras sometimes triggered by external noises, normal conventional magnetic resonance imaging (MRI), good response to antiepileptic treatment, and overall benign outcome. The same phenotype is shared by sporadic and familial cases with complex inheritance. Mutations in the LGI1 gene are found in about 50% of ADLTE families and 2% of sporadic cases. LGI1 shows no homology with known ion channel genes. Recent findings suggest that LGI1 may exert multiple functions, but it is not known which of them is actually related to lateral temporal epilepsy.
Familial mesial temporal lobe epilepsies: Clinical and genetic features
Authors: Gambardella Antonio , Labate Angelo , Giallonardo AnnaTeresa , Aguglia Umberto
Published: May 2009

Familial mesial temporal lobe epilepsy (FMTLE) was first described as a benign syndrome with prominent psychic and autonomic seizures and no association with hippocampal sclerosis (HS) or febrile seizures (FS). Better definition of the syndrome allowed identification of more heterogeneous phenotypes with mild to severe epileptic disorders, and a variable association with HS and FS. The genetics of these conditions is largely unknown and the hope for the future is that the identification of FMTLE genes will lead to more appropriate approaches for the diagnosis and treatment of TLE.
The syndrome gelastic seizures–hypothalamic hamartoma: Severe, potentially reversible encephalopathy
Authors: Striano Salvatore , Striano Pasquale , Coppola Antonietta , Romanelli Pantaleo
Published: May 2009

Hypothalamic hamartoma (HH) is the pathologic hallmark of a spectrum of epileptic conditions, ranging from a mild form of epilepsy, whose seizures are an urge to laugh without cognitive defects, to the fully developed syndrome of early onset gelastic seizures (GS) associated with precocious puberty and the evolution to a catastrophic epilepsy syndrome. However, a refractory focal or generalized epilepsy develops during the clinical course in nearly all cases. Neurophysiologic and neuroimaging studies have assessed the role of HH in the generation of the GS as well as in the process of secondary epileptogenesis. Electrophysiologic properties of small γ‐aminobutyric acid (GABA)ergic, spontaneously firing neurons might explain the intrinsic epileptogenicity of HH. Surgical ablation of the HH can reverse both epilepsy and encephalopathy. Gamma‐knife radiosurgery and image‐guided robotic radiosurgery can be useful and safe approaches for treatment, in particular of small HH.
Can Serotonin Transporter Genotype Predict Craving in Alcoholism?
Authors: Ait‐Daoud Nassima , Roache John D. , Dawes Michael A. , Liu Lei , Wang Xin‐Qun , Javors Martin A. , Seneviratne Chamindi , Johnson Bankole A.
Published: May 2009

Background:  We hypothesize that functional control of the serotonergic system is regulated in part by differential expression of the serotonin (5‐HT) transporter (5‐HTT). Alcohol‐dependent individuals with the LL/LS genotype (L‐carriers), compared with those with the SS genotype, have a lower 5‐HT neurotransmission, which we hypothesize would be associated with higher craving for alcohol among L‐carriers. We hypothesize further that acute peripheral depletion of tryptophan (5‐HT’s precursor), while further reducing 5‐HT function, might decrease auto‐inhibition of 5‐HT neuronal firing, thereby increasing 5‐HT neurotransmission transiently and lowering alcohol craving.

Methods:  We tested these hypotheses by examining whether in 34 Hispanic alcohol‐dependent individuals subjective and physiological cue craving for alcohol differed by genotype, age of onset of problem drinking, and tryptophan availability.

Results:  On subjective “urge to drink” and “crave for a drink,” we found a significant (p < 0.05) main effect of genotype and cue, as well as an interaction among genotype, age of onset of problem drinking, and tryptophan depletion. For the physiological measure of pulse, there was a main effect of genotype. L‐carriers had higher craving than their SS counterparts, an effect that decreased under tryptophan depletion. While craving in L‐carriers increased with an earlier age of onset of problem drinking, the opposite effect was seen in those with the SS genotype.

Conclusion:  These results not only provide support for the hypothesis that alcoholics who are L‐carriers have greater alcohol craving and possibly greater propensity for drinking but also propose that there is an important 5‐HTT gene‐by‐environment interaction that alters cue craving response for alcohol.
Associations Among GABRG1, Level of Response to Alcohol, and Drinking Behaviors
Authors: Ray Lara A. , Hutchison Kent E.
Published: May 2009

Background:  Recent studies of the genetics of alcoholism have focused on a cluster of genes encoding for γ‐aminobutyric acid (GABAA) receptor subunits, which is thought to play a role in the expression of addiction phenotypes. This study examined allelic associations between 2 single nucleotide polymorphisms (SNPs) of the GABRG1 gene (rs1391166 and rs1497571) and alcohol phenotypes, namely level of response to alcohol, alcohol use patterns, and alcohol‐related problems.

Method:  Participants were non‐treatment‐seeking seeking hazardous drinkers (n = 124) who provided DNA samples, participated in a face‐to‐face interview for level of response to alcohol, and completed a series of drinking and individual differences measures.

Results:  Analyses revealed that a SNP of the GABRG1 gene (rs1497571) was associated with level of response to alcohol and drinking patterns in this subclinical sample. Follow‐up mediational analyses were also conducted to examine putative mechanisms underlying these associations.

Discussion:  These findings replicate and extend recent research suggesting that genetic variation at the GABRG1 locus may underlie the expression of alcohol phenotypes, including level of response to alcohol.
Influence of Alcohol Use Experience and Motivational Drive on College Students’ Alcohol‐Related Cognition
Authors: O’Connor Roisin M. , Colder Craig R.
Published: May 2009

Background:  Cognitive processes are thought to be pivotal to risk for heavy drinking. However, few studies have examined the alcohol cue‐activated positive and negative semantic memory networks that may be pivotal to drinking behavior. Moreover, much is to be understood about the influences of cognitive processes, particularly in high‐risk drinking samples such as college students. The current study examines the sequential process of alcohol cues activating valenced semantic memory networks, and the influences of prior drinking experience and individual differences in motivational drive on this automatic (implicit) cognitive process.

Methods:  Participants (N = 138, 52% women) were college freshmen prescreened to represent the full range of drinking experience (i.e., current abstainers, light and heavy drinkers). Participants completed self‐reports of past month alcohol use, and individual differences in behavioral inhibition system (BIS) and behavioral approach/activation system (BAS). Alcohol cue‐elicited positive and negative semantic memory networks were assessed using a priming task.

Results:  Results from the priming task revealed that for light drinkers alcohol cues were equally as likely to activate positive and negative semantic memory networks, suggesting relatively neutral cue‐elicited alcohol attitudes. Conversely, for heavy drinkers, alcohol cues more readily activated positive relative to negative semantic memory networks, suggesting relatively positive cue‐elicited alcohol attitudes. Furthermore, positive alcohol cue‐elicited semantic memory networks (positive attitudes) were evident for individuals characterized by a strong BAS and weak BIS (as hypothesized) and those characterized by a weak BAS and weak BIS.

Conclusions:  The findings suggest that alcohol‐cue elicited positive semantic memory networks may be pivotal to risk for heavy drinking. Specifically, it is via the influence on this cognitive process that prior drinking experience and individual differences in motivational drive, respectively, may maintain and predispose individuals to risk for heavy alcohol use.
Cost‐Effectiveness of Screening for Unhealthy Alcohol Use with %Carbohydrate Deficient Transferrin: Results From a Literature‐Based Decision Analytic Computer Model
Authors: Kapoor Alok , Kraemer Kevin L. , Smith Kenneth J. , Roberts Mark S. , Saitz Richard
Published: May 2009

Background:  The %carbohydrate deficient transferrin (%CDT) test offers objective evidence of unhealthy alcohol use but its cost‐effectiveness in primary care conditions is unknown.

Methods:  Using a decision tree and Markov model, we performed a literature‐based cost‐effectiveness analysis of 4 strategies for detecting unhealthy alcohol use in adult primary care patients: (i) Questionnaire Only, using a validated 3‐item alcohol questionnaire; (ii) %CDT Only; (iii) Questionnaire followed by %CDT (Questionnaire‐%CDT) if the questionnaire is negative; and (iv) No Screening. For those patients screening positive, clinicians performed more detailed assessment to characterize unhealthy use and determine therapy. We estimated costs using Medicare reimbursement and the Medical Expenditure Panel Survey. We determined sensitivity, specificity, prevalence of disease, and mortality from the medical literature. In the base case, we calculated the incremental cost‐effectiveness ratio (ICER) in 2006 dollars per quality‐adjusted life year ($/QALY) for a 50‐year‐old cohort.

Results:  In the base case, the ICER for the Questionnaire‐%CDT strategy was $15,500/QALY compared with the Questionnaire Only strategy. Other strategies were dominated. When the prevalence of unhealthy alcohol use exceeded 15% and screening age was <60 years, the Questionnaire‐%CDT strategy costs less than $50,000/QALY compared to the Questionnaire Only strategy.

Conclusions:  Adding %CDT to questionnaire‐based screening for unhealthy alcohol use was cost‐effective in our literature‐based decision analytic model set in typical primary care conditions. Screening with %CDT should be considered for adults up to the age of 60 when the prevalence of unhealthy alcohol use is 15% or more and screening questionnaires are negative.
Mood‐Related Drinking Motives Mediate the Familial Association Between Major Depression and Alcohol Dependence
Authors: Young‐Wolff Kelly C. , Kendler Kenneth S. , Sintov Nicole D. , Prescott Carol A.
Published: May 2009

Background:  Major depression and alcohol dependence co‐occur within individuals and families to a higher than expected degree. This study investigated whether mood‐related drinking motives mediate the association between major depression and alcohol dependence, and what the genetic and environmental bases are for this relationship.

Methods:  The sample included 5,181 individuals from the Virginia Adult Twin Study of Psychiatric and Substance Use Disorders, aged 30 and older. Participants completed a clinical interview which assessed lifetime major depression, alcohol dependence, and mood‐related drinking motives.

Results:  Mood‐related drinking motives significantly explained the depression‐alcohol dependence relationship at both the phenotypic and familial levels. Results from twin analyses indicated that for both males and females, the familial factors underlying mood‐related drinking motives accounted for virtually all of the familial variance that overlaps between depression and alcohol dependence.

Conclusions:  The results are consistent with an indirect role for mood‐related drinking motives in the etiology of depression and alcohol dependence, and suggest that mood‐related drinking motives may be a useful index of vulnerability for these conditions.
The Role of Champions in the External Commercialization of Knowledge*
Authors: Lichtenthaler Ulrich , Ernst Holger
Published: May 2009

Besides applying knowledge in their own products or services, firms may externally commercialize their knowledge assets (e.g., by means of outlicensing). The literature on champions, however, has focused on internal innovation. This gap in prior research is particularly remarkable as the potential for promoting external knowledge exploitation is high. Some pioneering firms realize great benefits, whereas most others experience major managerial difficulties. This paper tests five hypotheses regarding the emergence and impact of champions of external knowledge exploitation with data from 152 firms across industries. The results of the questionnaire‐based study demonstrate the relevance of champions of external knowledge exploitation. Championing constitutes an essential success factor and has strongly contributed to the recent increase in external knowledge commercialization. These findings help to explain the discrepancies between the few successful and the majority of unsuccessful firms. Beyond existing insights, the emergence of champions is affected by external determinants in addition to internal determinants. There is an inverted U‐shaped relationship between championing and the internal determinants, that is, organizational climate and active strategy. Moreover, there is a negative relationship between championing and market imperfection and an inverted U‐shaped relationship between championing and competitive intensity, which both constitute external determinants of championing. In contrast to the traditional understanding, champions tend to emerge in supportive environments, in which internal and external barriers are relatively low. This surprising finding calls for rethinking the role and motivation of champions.
Virtual Customer Environments: Testing a Model of Voluntary Participation in Value Co‐creation Activities
Authors: Nambisan Satish , Baron Robert A.
Published: May 2009

An increasing number of firms are hosting virtual customer environments (VCEs) to involve their customers in product development and product support activities. While the benefits to companies from hosting such VCEs are clear, another closely related issue has received far less attention: Why do customers participate voluntarily in value cocreation (here, product support) activities in such virtual customer environments? This study seeks to answer this question by developing and testing a conceptual model that draws on the uses and gratifications approach to consider an integrated set of four benefits that customers gain from their interactions in VCEs. The research model also incorporates the interaction‐based antecedents of these customer benefits. Drawing on concepts and insights from the areas of computer‐mediated communication and brand communities, the key characteristics of customers' interactions in the VCE are identified and related to the aforementioned four types of benefits. The study hypotheses are tested using data collected from customer participants of the VCEs of two firms, Microsoft and IBM. The dependent variable, customers' actual participation in the VCE, is operationalized as a time‐lagged variable, and the data for this are sourced from the Netscan database. Results offer strong support for the model and indicate that customers' participation in product support activities in a VCE is motivated not just by their “citizenship” or norm‐related behavior but stems primarily from their beliefs concerning the benefits of engaging in such activities. Results also show the impact of key interaction characteristics of VCEs on such perceived benefits and imply the need for firms to carefully design their VCEs to enhance customers' perceptions regarding potential benefits. The research model and the findings hold important implications for research and practice in customer coinnovation and product development. The model provides the basis for identifying the appropriate set of VCE design features. Companies can test the efficacy of their VCE design features by focusing on how such features augment the four types of benefits discussed and thereby ensure continued customer participation. The study findings also hold broader implications for practice in the customer relationship management area, particularly with regard to the potential to combine customers' VCE interactions with appropriate offline product‐related activities and to view the VCE as an integral element of the firm's overall customer relationship management initiative.
Managing Creative People: Lessons in Leadership for the Ideas Economy by Gordon Torr
Authors: Kingston George
Published: May 2009

Books reviewed in this issue:

Managing Creative People: Lessons in Leadership for the Ideas Economy

Triple C Model of Project Management: Communication, Cooperation, and Coordination

Tuned In: Uncover the Extraordinary Opportunities that Lead to Business Breakthroughs

Customer Visits
A Prospective Randomized Study to Assess the Efficacy of Rate and Site of Atrial Pacing on Long‐Term Development of Atrial Fibrillation
Authors: LAU CHU‐PAK , WANG CHUN‐CHIEH , NGARMUKOS TACHAPONG , KIM YOU‐HO , KONG CHI‐WOON , OMAR RAZALI , SRIRATANASATHAVORN CHARN , MUNAWAR MUHAMMAD , KAM RUTH , LEE KATHY LF , LAU ELIZABETH OI‐YAN , TSE HUNG‐FAT ,   SAFE Study Steering Committee for the SAFE Study Group
Published: May 2009

The Septal Pacing for Atrial Fibrillation Suppression Evaluation (SAFE) study is a single‐blinded, parallel randomized designed multicenter study in pacemaker indicated patients with paroxysmal atrial fibrillation (AF). The objective is to evaluate whether the site of atrial pacing–‐conventional right atrial appendage versus low atrial septal—with or without atrial overdrive pacing will influence the development of persistent AF. The study will provide a definitive answer to whether a different atrial pacing site or the use of AF suppression pacing or both can give incremental antiarrhythmic benefit when one is implanting a device for a patient with a history of paroxysmal AF.
Three‐dimensional electron microscopic reconstruction of intracellular organellar arrangements in vascular smooth muscle – further evidence of nanospaces and contacts
Authors: Tong Wing Chiu , Sweeney Michele , Jones Carolyn J. P. , Zhang Henggui , O’Neill Stephen C. , Prior Ian , Taggart Michael J.
Published: May 2009

The sarcoplasmic reticulum (SR) of smooth muscle is crucial for appropriate regulation of Ca2+ signalling. In visceral and vascular smooth muscles the SR is known to periodically lie in close register, within a few nanometres, to the plasma membrane. Recent work has focussed on reconstructions of the ultrastructural arrangement of this so‐called peripheral SR that may be important for the genesis of phenomena such as Ca2+ sparks. Here, we turn our attention to vascular smooth muscle and explore the 3‐dimensional (3D) ultrastructural positioning of SR found deeper in the cell that is involved in the propagation of Ca2+ waves. We use digital reconstruction and volume rendering of serial electron microscopic sections from isolated resistance arteries, pressurized in vitro to mimic cellular geometric conformations anticipated in vivo, to map SR positioning. We confirm that these central portions of SR are in close register with mitochondria and the nucleus with all three organelles tightly enveloped by a myofilament/cytoskeletal lattice. Nanospacings between the SR and individual mitochondria are visible and in three dimensions as the SR contorts to accommodate these organelles. Direct connection of the SR and nuclear membranes is confirmed. Such 3D positioning of centrally located SR further informs us of its likely role in the manifestation of spatiotemporal Ca2+ dynamics: signal encoding may be facilitated by spatially directed release of Ca2+ to influence several processes crucial to vascular smooth muscle and resistance artery function including myofilament activation by Ca2+ waves, mitochondrial respiration and gene transcription.
Identification of three in‐frame deletion mutations in MYH9 disorders suggesting an important hot spot for small rearrangements in MYH9 exon 24
Authors: Miyazaki Koji , Kunishima Shinji , Fujii Wataru , Higashihara Masaaki
Published: May 2009

MYH9 disorders include hereditary macrothrombocytopenias with leukocyte inclusion bodies. Among more than 200 genetically confirmed families, the vast majority of cases exhibit single point mutations including substitutions and deletions of the COOH‐terminus in the protein‐coding sequence of MYH9. Only four in‐frame deletions have been reported to date. In the current study, we describe three in‐frame deletions including p.E1084del, p.E1066_A1072del and p.G1055_Q1068del, all of which are localized to exon 24. Interestingly, these three deletions were found to induce the diverse clinical manifestations on the non‐hematological symptoms, while they equally demonstrated type I staining of inclusion bodies. As a result of these findings, we suggest that exon 24 represents a potential ‘hot spot’ for unequal homologous recombination, which may generate in‐frame deletions in the coiled‐coil rod of non‐muscle myosin heavy chain‐IIA. The exact length and position of these deletions may also determine the severity of the non‐hematological manifestations, however does not appear to affect the morphology of the leukocyte inclusion bodies. These findings further our current understanding of the molecular pathogenesis underlying MYH9 disorders.
Acute megakaryoblastic leukemia in a child with the MLL‐AF4 fusion gene
Authors: Takita Junko , Motomura Ai , Koh Katsuyoshi , Ida Kohmei , Taki Tomohiko , Hayashi Yasuhide , Igarashi Takashi
Published: May 2009

Mixed‐lineage leukemia (MLL) rearrangements are commonly observed in childhood acute lymphoblastic and myeloid leukemia, as well as therapy‐related leukemia. However, the occurrence of MLL rearrangements in acute megakaryoblastic leukemia (AMKL) is very rare. We report a pediatric case of AMKL with the MLL‐AF4 fusion transcript. MLL‐AF4 is derived from t(4;11)(q21:q23) and occurs exclusively in B‐cell lineage leukemia. To our knowledge, MLL‐AF4 as well as t(4;11)(q21:q23) has not been reported in adult and childhood AMKL. Thus, our case provides new insight into the molecular mechanisms of MLL‐AF4‐associated leukemia.
Assessing Credit Risk in an Agricultural Loan Portfolio
Authors: Pederson Glenn D. , Zech Lyubov
Published: May 2009

We show that agricultural lenders can implement a credit risk model that uses their loan portfolio data and complies with the new Basel Capital Accord without requiring Merton‐type model assumptions about underlying asset price volatility. A credit risk model is described and calibrated to the loan portfolio of a farm lender. The model is used to produce plausible estimates of expected loss, unexpected loss, and credit value‐at‐risk (VaR) at the portfolio and subportfolio (sector) levels. The lender could use these kinds of estimates to meet regulatory requirements or to adjust the level of capital in response to changing economic conditions.

Nous montrons que les prêteurs agricoles peuvent appliquer un modèle de risque de crédit qui permet d'utiliser des données tirées de leur portefeuille de prêts et qui respecte le nouvel accord de Bâle sur les fonds propres, sans qu'il soit nécessaire d'utiliser les hypothèses du modèle de Merton sur la volatilité des prix des actifs. Nous avons décrit un modèle de risque de crédit et l'avons calibré en fonction du portefeuille de prêts d'un prêteur agricole. Le modèle est utilisé pour effectuer des estimations plausibles quant aux pertes prévues, aux pertes imprévues et à la valeur à risque au niveau du portefeuille et du sous‐portefeuille. Le prêteur pourrait utiliser ce genre d'estimations pour respecter les exigences réglementaires ou pour rajuster le niveau de fonds propres en fonction de l'évolution de la conjoncture économique.
Risk and Nitrogen Application Levels
Authors: Rajsic Predrag , Weersink Alfons , Gandorfer Markus
Published: May 2009

Stochastic weather and soil conditions are the suggested reasons why farmers tend to apply more than the recommended levels of nitrogen. This study found that uncertainty plays a role in the application decision of farmers but not in the manner typically assumed. Using a time series of field trials of corn yield to nitrogen for the same site, nitrogen was found to be a risk‐increasing input suggesting that uncertainty should decrease, rather than increase, a risk‐averse farmer's rate of nitrogen application. Similarly, viewing risk as a profit shortfall, in which fertilizer acts in the role of insurance, was also not supported with the empirical results. Instead, the key role of uncertainty is its impact on expected profits. Increasing application rates leads to lower returns in most years but the increase in profits generated under favorable growing conditions results in greater expected profits with a high application strategy.

Les conditions météorologiques et pédologiques aléatoires seraient les raisons pour lesquelles les agriculteurs tendent à appliquer des doses d'azote supérieures aux doses recommandées. Selon la présente étude, l'incertitude joue un rôle dans les décisions d'application des agriculteurs, mais d'une façon différente de celle généralement supposée. À l'aide d'une série chronologique d'essais en champ mesurant le rendement du maïs en fonction de l'azote dans le même site, nous avons trouvé que l'azote était un intrant qui augmentait les risques, ce qui laisse supposer que l'incertitude devrait faire diminuer, plutôt que de faire augmenter, la dose d'application d'azote dans le cas d'un producteur qui craint les risques. De même, considérer le risque de baisse des profits où l'engrais assume le rôle d'assurance n'a pas été appuyé par les résultats empiriques. Le rôle clé de l'incertitude est son impact sur les profits prévus. L'augmentation des doses d'application entraîne une diminution des rendements la plupart des années, mais l'augmentation des profits générés dans des conditions de croissance favorables entraîne des profits prévus plus élevés grâce à une meilleure stratégie d'application.
Threshold Effects and Asymmetric Price Adjustments in U.S. Dairy Markets
Authors: Awokuse Titus O. , Wang Xiaohong
Published: May 2009

Recent volatility in food prices and the growing disparity between prices at various stages of the marketing channel has generated much interest among agricultural producers, consumers, and policy makers. This study examines the effect of nonlinear threshold dynamics on asymmetric price transmission for three U.S. dairy products (butter, cheese, and fluid milk) using threshold error correction models. The empirical result suggests that price transmission of changes between producer and retail stages of the marketing chain is asymmetric for butter and fluid milk, but not for cheese prices. Also, this paper's findings indicate that conclusions about price asymmetries depend on the model specification assumptions made about symmetry and threshold effects. Thus, previous studies that assumed symmetric behavior and ignored threshold effects may be misleading.

La récente volatilité des prix des produits alimentaires et la disparité croissante entre les prix observés aux divers échelons du réseau de distribution ont suscité l'attention des producteurs agricoles, des consommateurs et des décideurs. La présente étude examine l'effet d'une dynamique non linéaire avec seuil sur la transmission asymétrique des prix dans le cas de trois produits laitiers aux États‐Unis (le beurre, le fromage et le lait de consommation), à l'aide de modèles à correction d'erreur avec seuil. Les résultats empiriques montrent que la transmission des variations de prix entre les producteurs agricoles et les détaillants est asymétrique dans le cas du beurre et du lait de consommation, mais ne l'est pas dans le cas du fromage. D'après les résultats de la présente étude, les conclusions concernant l'asymétrie des prix dépendent des hypothèses posées sur la symétrie et les effets de seuil. Par conséquent, les études antérieures dans lesquelles on a supposé un comportement symétrique et ignoré les effets de seuil pourraient induire en erreur.
Isolation and characterization of macaroni penguin (Eudyptes chrysolophus) microsatellite loci and their utility in other penguin species (Spheniscidae, AVES)
Authors: AHMED SOPHIA , HART TOM , DAWSON DEBORAH A. , HORSBURGH GAVIN J. , TRATHAN PHILIP N. , ROGERS ALEX D.
Published: May 2009

We report the characterization of 25 microsatellite loci isolated from the macaroni penguin (Eudyptes chrysolophus). Thirteen loci were arranged into four multiplex sets for future genetic studies of macaroni penguin populations. All 25 loci were tested separately in each of four other penguin species [Adélie penguin (Pygoscelis adeliae), chinstrap penguin (Pygoscelis antarctica), gentoo penguin (Pygoscelis papua) and king penguin (Aptenodytes patagonicus)]. Between eight and 12 loci were polymorphic per species. These loci are expected to be useful for studies of population genetic structure in a range of penguin species.
Prominence and consumer search
Authors: Armstrong Mark , Vickers John , Zhou Jidong
Published: May 2009

This article examines the implications of “prominence” in search markets. We model prominence by supposing that the prominent firm will be sampled first by all consumers. If there are no systematic quality differences among firms, we find that the prominent firm will charge a lower price than its less prominent rivals. Making a firm prominent will typically lead to higher industry profit but lower consumer surplus and welfare. The model is extended by introducing heterogeneous product qualities, in which case the firm with the highest‐quality product has the greatest incentive to become prominent, and making it prominent will boost industry profit, consumer surplus, and welfare.
Endogenous preferential treatment in centralized admissions
Authors: Chiu Y. Stephen , Weng Weiwei
Published: May 2009

We study a model of centralized admissions in which schools are allowed to pre‐commit to admitting qualified applicants who rank them as their top choices over more qualified applicants who do not. A less popular school may use the pre‐commitment to steal applicants who otherwise would not choose it as their top choice (the stealing motive); a popular school may use the pre‐commitment to prevent its own applicants from being stolen (the preemptive motive). We identify the conditions for these two motives to exist. We also clarify the relationship of this phenomenon with that of pre‐arrangement of school places.
Preferred suppliers in auction markets
Authors: Burguet Roberto , Perry Martin K.
Published: May 2009

This article examines agreements between a buyer and one of the suppliers which increase their joint surplus. The provisions of such agreements depend on the buyer's ability to design the rules of the final procurement auction. When the buyer does not have this ability, their joint surplus can be increased by an agreement which grants to the preferred supplier a right of first refusal on the lowest price from the other suppliers. When the buyer has this ability, their joint surplus can be maximized by a revelation game for the cost of the preferred supplier and a reserve price based on that cost.
Implementing high‐powered contracts to motivate intertemporal effort supply
Authors: Chu Leon Yang , Sappington David E.M.
Published: May 2009

We characterize the optimal contract between a principal and a risk‐neutral, wealth‐constrained agent when an adverse selection problem follows a moral hazard problem. The optimal contract in this setting often is more steeply sloped for the largest output levels than is the optimal contract in either the standard moral hazard setting or the standard adverse selection setting. The large incremental rewards for exceptional performance motivate the agent to deliver substantial effort both before and after he acquires privileged information about the production environment.
Negotiating contract types and contract clauses in the German construction industry during the Third Reich
Authors: Streb Jochen
Published: May 2009

This article examines the determinants of contractual form and renegotiations in the German construction industry during the Third Reich. At the beginning of World War II, firms dealt with growing uncertainty by convincing procurement agencies either to use cost‐plus contracts or to include an additional risk premium in fixed‐price contracts. In the later years of the war, procurement agencies initiated renegotiations over contract clauses to reduce the extraordinary profits resulting from information rents and high‐risk premiums. This regulatory course undermined the credibility of the regulatory commitment, thereby weakening the incentives of the fixed‐price contracts still in use.
Design Formulas of Blind End Closures for High Pressure Vessels
Authors: Dixon R. D. , Perez E. H.
Published: May 2009

The available design formulas for flat heads and blind end closures in the ASME Code, Section VIII, Divisions 1 and 2 are based on bending theory and do not apply to the design of thick flat heads used in the design of high pressure vessels. This paper presents new design formulas for thickness requirements and determination of peak stresses and stress distributions for fatigue and fracture mechanics analyses in thick blind ends. The use of these proposed design formulas provide a more accurate determination of the required thickness and fatigue life of blind ends. The proposed design formulas are given in terms of the yield strength of the material and address the fatigue strength at the location of the maximum stress concentration factor. Introduction of these new formulas in a nonmandatory appendix of Section VIII, Division 3 is recommended after committee approval.
Thermal Elastic-Plastic Analysis Considering Temperature Rise by Rapid Plastic Deformation in Undermatched Joints
Authors: Mochizuki Masahito , An Gyu-Baek , Toyoda Masao
Published: May 2009

The characteristics of dynamic strength and fracture in structural steels and their welded joints particularly for pipelines should be evaluated based on the effects of the strain rate and service temperature. The temperature, however, rises so rapidly in structures due to the plastic work under the high strain rate such as ground sliding by earthquake when the effect of the temperature cannot be negligible for the dynamic fracture. It is difficult to predict or measure the temperature rise history with the corresponding stress-strain behavior, including the region beyond the uniform elongation, though the behavior at the large strain region after the maximum loading point is very important for the evaluation of fracture. In this paper, the coupling phenomena of the temperature and stress-strain fields under dynamic loading were simulated by using the finite element method. A modified rate-temperature parameter was defined by accounting for the effect of the temperature rise under rapid plastic deformation, and it was applied to the fully coupled analysis between the heat conduction and thermal elastic-plastic behavior. The temperature rise and stress-strain behavior, including the coupling phenomena, were studied including the region beyond the maximum loading point in structural steels and their undermatched joints, and then compared with the measured values.