bluuebunny/crossref_metadata_2025 huggingface dataset:
Oxidative Stress in Parkinson's Disease
Authors: Zhou Chun , Huang Yong , Przedborski Serge
Published: July 2010

Parkinson's disease (PD) is a common adult‐onset neurodegenerative disorder. Typically PD is a sporadic neurological disorder, and over time affected patients see their disability growing and their quality of life declining. Oxidative stress has been hypothesized to be linked to both the initiation and the progression of PD. Preclinical findings from both in vitro and in vivo experimental models of PD suggest that the neurodegenerative process starts with otherwise healthy neurons being hit by some etiological factors, which sets into motion a cascade of deleterious events. In these models initial molecular alterations in degenerating dopaminergic neurons include increased formation of reactive oxygen species, presumably originating from both inside and outside the mitochondria. In the 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP) mouse model of PD, time‐course experiments suggest that oxidative stress is an early event that may directly kill some of the dopaminergic neurons. In this model it seems that oxidative stress may play a greater role in the demise of dopaminergic neurons indirectly by activating intracellular, cell death‐related, molecular pathways. As the neurodegenerative process evolves in the MPTP mouse model, indices of neuroinflammation develop, such as microglial activation. The latter increases the level of oxidative stress to which the neighboring compromised neurons are subjected to, thereby promoting their demise. However, these experimental studies have also shown that oxidative stress is not the sole deleterious factor implicated in the death of dopaminergic neurons. Should a similar multifactorial cascade underlie dopaminergic neuron degeneration in PD, then the optimal therapy for this disease may have to rely on a cocktail of agents, each targeting a different critical component of this hypothesized pathogenic cascade. If correct, this may be a reason why neuroprotective trials using a single agent, such as an antioxidant, have thus far generated disappointing results.
Regulation of Forkhead Transcription Factor FoxO3a Contributes to Calorie Restriction‐induced Prevention of Alzheimer's Disease‐type Amyloid Neuropathology and Spatial Memory Deterioration
Authors: Qin Weiping , Zhao Wei , Ho Lap , Wang Jun , Walsh Kenneth , Gandy Sam , Pasinetti Giulio Maria
Published: July 2010

Forkhead transcription factor FoxO3a, also known as DAF‐16 in Caenorhabditis elegans, is a key regulator of the insulin receptor (IR)/insulin‐like growth factor‐I signaling pathway mediated extension of life span in worms and yeast. In this study, we report that calorie restriction (CR)‐mediated activation of the IR signaling pathway leads to hyperphosphorylation of FoxO3a transcription factor and, consequently, its exclusion from the nucleus. This inactivation of FoxO3a activity is correlated with attenuation of Alzheimer's disease (AD)‐type amyloid neuropathology and with preservation of spatial reference memory in the Tg2576 mouse model of AD. Further, in vitro studies reveal that exogenous expression of viral, triple‐mutant, constitutively active FoxO3a resulting in increased nuclear FoxO3a activity in primary neuron cultures derived from Tg2576 mouse embryos, causally promotes AD amyloid‐β peptide (Aβ) levels by inhibiting nonamyloidogenic α‐secretase activity, indicating the existence of an inverse correlation between FoxO3a activity and cerebral Aβ amyloidosis. Moreover, we report for the first time that the exclusion of the FoxO3a transcription factor from the nucleus in combination with inhibition of nuclear FoxO3a activity by SIRT1‐mediated deacetylation in response to CR is a mechanism resulting in the repression of Rho‐associated protein kinase‐1 gene expression, thereby activating nonamyloidogenic α‐secretase processing of the amyloid precursor protein and lowering Aβ generation. This study provides a novel metabolic pathway for prevention and/or treatment of AD.
Impairing the Mitochondrial Fission and Fusion Balance: A New Mechanism of Neurodegeneration
Authors: Knott Andrew B. , Bossy‐Wetzel Ella
Published: July 2010

Mitochondrial dysfunction is a common characteristic of all neurodegenerative diseases. However, the cause of this dysfunction remains a mystery. Here, we discuss the potential role of mitochondrial fission and fusion in the onset and progression of neurodegenerative diseases. Specifically, we propose that an imbalance in mitochondrial fission and fusion may underlie both familial and sporadic neurodegenerative disorders. There is substantial evidence that links disruption of the mitochondrial fission and fusion equilibrium, resulting in abnormally long or short mitochondria, to neurodegeneration. First, hereditary mutations in the mitochondrial fusion GTPases optic atrophy‐1 and mitofusin‐2 cause neuropathies in humans. In addition, recent findings report increased mitochondrial fission in Parkinson's disease (PD) models and induction of mitochondrial fission by two proteins, PTEN‐induced kinase 1 and parkin, which are mutant in familial forms of PD. Furthermore, mutant huntingtin, the disease‐causing protein in Huntington's disease, alters mitochondrial morphology and dynamics. Rotenone, a pesticide and inducer of PD symptoms, and amyloid‐β peptide, which is causally linked to Alzheimer's disease, initiate mitochondrial fission. Finally, mitochondrial fission is an early event in ischemic stroke and diabetic neuropathies. In sum, a growing body of research suggests that a better understanding of mitochondrial fission and fusion and the regulatory factors involved may lead to improved treatments and cures for neurodegenerative diseases.
STAT3α Is Oncogenic for Endometrial Carcinoma Cells and Mediates the Oncogenic Effects of Autocrine Human Growth Hormone
Authors: Tang Jian-Zhong , Kong Xiang-Jun , Banerjee Arindam , Muniraj Nethaji , Pandey Vijay , Steiner Michael , Perry Jo K. , Zhu Tao , Liu Dong-Xu , Lobie Peter E.
Published: July 2010

We herein demonstrate an oncogenic role for signal transducer and activator of transcription (STAT)-3α (the full length STAT3 isoform), which also mediates autocrine human GH (hGH)-stimulated oncogenicity, in human endometrial carcinoma (EC) cells. Autocrine hGH stimulated Y705 phosphorylation of STAT3 and STAT3-mediated transcriptional activity in a SRC and Janus-2 Kinase dependent manner in human EC cell lines. Forced expression of a constitutively active variant of STAT3α increased proliferation, anchorage-independent, three-dimensional (3D) Matrigel, and xenograft growth and promoted epithelial-mesenchymal transition, migration, and invasion of EC cells. Conversely, the oncogenic capacity of EC cells was significantly impaired by treatment with JSI-124, an inhibitor of STAT3 phosphorylation and activity, small interfering RNA-mediated depletion of STAT3α, or a dominant-negative variant of STAT3α. Furthermore, the enhanced EC cell oncogenicity stimulated by autocrine hGH, was also abrogated by functional inhibition or small interfering RNA-mediated depletion of STAT3α. STAT3α may therefore be a common mediator of oncogenic signaling pathways stimulating progression of EC.
The Endometrial Response to Chorionic Gonadotropin Is Blunted in a Baboon Model of Endometriosis
Authors: Sherwin J. R. A. , Hastings J. M. , Jackson K. S. , Mavrogianis P. A. , Sharkey A. M. , Fazleabas A. T.
Published: July 2010

Endometriosis-associated infertility has a multifactorial etiology. We tested the hypothesis that the endometrial response to the early embryonic signal, human chorionic gonadotropin (hCG), alters over time in a nonhuman primate model of endometriosis. Animals with experimental or spontaneous endometriosis were treated with hCG (30 IU/d), from d 6 after ovulation for 5 d, via an oviductal cannula. Microarray analysis of endometrial transcripts from baboons treated with hCG at 3 and 6 months of disease (n = 6) identified 22 and 165 genes, respectively, whose levels differed more than 2-fold compared with disease-free (DF) animals treated with hCG (P < 0.01). Quantitative RT-PCR confirmed abnormal responses of known hCG-regulated genes. APOA1, SFRP4, and PAPPA, which are normally down-regulated by hCG were up-regulated by hCG in animals with endometriosis. In contrast, the ability of hCG to induce SERPINA3 was lost. Immunohistochemistry demonstrated dysregulation of C3 and superoxide dismutase 2 proteins. We demonstrate that this abnormal response to hCG persists for up to 15 months after disease induction and that the nature of the abnormal response changes as the disease progresses. Immunohistochemistry showed that this aberrant gene expression was not a consequence of altered LH/choriogonadotropin receptor distribution in the endometrium of animals with endometriosis. We have shown that endometriosis induces complex changes in the response of eutopic endometrium to hCG, which may prevent the acquisition of the full endometrial molecular repertoire necessary for decidualization and tolerance of the fetal allograft. This may in part explain endometriosis-associated implantation failure.
Monetary Policy and Multiple Equilibria
Authors: Benhabib Jess , Schmitt-Grohé Stephanie , Uribe Martín
Published: July 2010

This paper characterizes conditions under which interest-rate feedback rules that set the nominal interest rate as an increasing function of the inflation rate induce aggregate instability by generating multiple equilibria. It shows that these conditions depend not only on the monetary-fiscal regime (as emphasized in the fiscal theory of the price level) but also on the way in which money is assumed to enter preferences and technology. It provides a number of examples in which, contrary to what is commonly believed, active monetary policy gives rise to multiple equilibria and passive monetary policy renders the equilibrium unique. (JEL E52, E31, E63)
What Hides Behind an Unemployment Rate: Comparing Portuguese and U.S. Labor Markets
Authors: Blanchard Olivier , Portugal Pedro
Published: July 2010

Behind similar unemployment rates in the United States and Portugal hide two very different labor markets. Unemployment duration is three times longer in Portugal than in the United States. Symmetrically, flows of workers into unemployment are three times lower in Portugal. These lower flows come in roughly equal proportions from lower job creation and destruction, and from lower worker flows given job creation and destruction. A plausible explanation is high employment protection in Portugal. High employment protection makes economies more sclerotic; but because it affects unemployment duration and worker flows in opposite directions, the effect on unemployment is ambiguous. (JEL E2, J3, J6)
The Provision of Public Goods Under Alternative Electoral Incentives
Authors: Lizzeri Alessandro , Persico Nicola
Published: July 2010

Politicians who care about the spoils of office may underprovide a public good because its benefits cannot be targeted to voters as easily as pork-barrel spending. We compare a winner-take-all system—where all the spoils go to the winner—to a proportional system—where the spoils of office are split among candidates proportionally to their share of the vote. In a winner-take-all system the public good is provided less often than in a proportional system when the public good is particularly desirable. We then consider the electoral college system and show that it is particularly subject to this inefficiency. (JEL D82, L15)
Proofs and Prototypes for Sale: The Licensing of University Inventions
Authors: Jensen Richard , Thursby Marie
Published: July 2010

Proponents of the Bayh-Dole Act argue that industrial use of federally funded research would be reduced without university patent licensing. Our survey of U.S. universities supports this view, emphasizing the embryonic state of most technologies licensed and the need for inventor cooperation in commercialization. Thus, for most university inventions, there is a moral-hazard problem with inventor effort. For such inventions, development does not occur unless the inventor's income is tied to the licensee's output by payments such as royalties or equity. Sponsored research from the licensee cannot by itself solve this problem. (JEL O31, O34, O38)
Dividends and Expropriation
Authors: Faccio Mara , Lang Larry H. P , Young Leslie
Published: July 2010

Whereas most U.S. corporations are widely held, the predominant form of ownership in East Asia is control by a family, which often supplies a top manager. These features of “crony capitalism” are actually more pronounced in Western Europe. In both regions, the salient agency problem is expropriation of outside shareholders by controlling shareholders. Dividends provide evidence on this. Group-affiliated corporations in Europe pay higher dividends than in Asia, dampening insider expropriation. Dividend rates are higher in Europe, but lower in Asia, when there are multiple large shareholders, suggesting that they dampen expropriation in Europe, but exacerbate it in Asia. (JEL G34, G35)
Information Gatekeepers on the Internet and the Competitiveness of Homogeneous Product Markets
Authors: Baye Michael R , Morgan John
Published: July 2010

We examine the equilibrium interaction between a market for price information (controlled by a gatekeeper) and the homogenous product market it serves. The gatekeeper charges fees to firms that advertise prices on its Internet site and to consumers who access the list of advertised prices. Gatekeeper profits are maximized in an equilibrium where (a) the product market exhibits price dispersion; (b) access fees are sufficiently low that all consumers subscribe; (c) advertising fees exceed socially optimal levels, thus inducing partial firm participation; and (d) advertised prices are below unadvertised prices. Introducing the market for information has ambiguous social welfare effects. (JEL D4, D8, M3, L13)
A Theory of Buyer-Seller Networks
Authors: Kranton Rachel E , Minehart Deborah F
Published: July 2010

This paper introduces a new model of exchange: networks, rather than markets, of buyers and sellers. It begins with the empirically motivated premise that a buyer and seller must have a relationship, a “link,” to exchange goods. Networks—buyers, sellers, and the pattern of links connecting them—are common exchange environments. This paper develops a methodology to study network structures and explains why agents may form networks. In a model that captures characteristics of a variety of industries, the paper shows that buyers and sellers, acting strategically in their own self-interests, can form the network structures that maximize overall welfare. (JEL D00, L00)
Optimal Incentives for Teams
Authors: Che Yeon-Koo , Yoo Seung-Weon
Published: July 2010

Much of the existing theory of incentives describes a static relationship that lasts for just one transaction. This static assumption is not only unrealistic, but the resulting predictions appear to be at odds with many work organizations. The current paper introduces possible long-term interaction among agents, and studies how the design of explicit incentives and work organizations can exploit, and interact with, the implicit incentives generated by the repeated interaction of the agents. The optimal incentive scheme is shown to display observed features of the increasingly popular “teams,” such as the use of low-powered, group incentives. (JEL D23, J33, J41, L23)
Competition and Custom in Economic Contracts: A Case Study of Illinois Agriculture
Authors: Young H. Peyton , Burke Mary A
Published: July 2010

Survey data suggest that cropsharing contracts exhibit a much higher degree of uniformity than is warranted by economic fundamentals. We propose a dynamic model of contract choice to explain this phenomenon. Landowners and tenants recontract periodically, taking into account expected returns as well as conformity with local practice. The resulting stochastic dynamical system is studied using techniques from statistical mechanics. The most likely states consist of patches where contractual terms are nearly uniform, separated by boundaries where the terms shift abruptly. These and other predictions of the model are borne out by survey data on agricultural contracts in Illinois. (JEL J43, C73)
Rising U.S. Earnings Inequality and Family Labor Supply: The Covariance Structure of Intrafamily Earnings
Authors: Hyslop Dean R
Published: July 2010

This paper studies the labor supply contributions to individual and family earnings inequality during the period of rising wage inequality in the early 1980's. Working couples have positively correlated labor market outcomes, which are almost entirely attributable to permanent factors. An intertemporal family labor supply model with this feature is used to estimate labor supply elasticities for husbands of 0.05, and wives of 0.40. This implies that labor supply explains little of the rising annual earnings inequality for married men, but over 20 percent of the rise in family inequality and 50 percent of the modest rise in female inequality. (JEL C23, J22)
Financial Markets and Firm Dynamics
Authors: Cooley Thomas F , Quadrini Vincenzo
Published: July 2010

Recent studies have shown that the dynamics of firms (growth, job reallocation, and exit) are negatively correlated with the initial size of the firm and its age. In this paper we analyze whether financial factors, in addition to technological differences, are important in generating these dynamics. We introduce financial-market frictions in a basic model of industry dynamics with persistent shocks and show that the combination of persistent shocks and financial frictions can account for the simultaneous dependence of firm dynamics on size (once we control for age) and on age (once we control for size). (JEL D21, G3, L2)
Effect of Kangaroo Mother Care on physical growth, breastfeeding and its acceptability
Authors: Gathwala Geeta , Singh Bir , Singh Jagjit
Published: July 2010

The aim of this study was to determine whether the implementation of Kangaroo Mother Care (KMC) to low birth weight infants would improve physical growth, breastfeeding and its acceptability. A randomized controlled trial was performed over 16 months in which 110 neonates were randomized into a KMC group and a control group using a random number table. The KMC group was subjected to KMC for at least 6 h per day. The babies also received KMC after moving from the neonatal intensive care unit and at home. The control group received standard care (incubator or open care system). Weight, length and occipitofrontal circumference (OFC) were measured weekly for three months. The acceptability of KMC by mothers and nursing staff was assessed on day 7 after the start of KMC using a questionnaire incorporating the Likert scale. Breastfeeding rates were calculated based on history at end of three months. The mean gestational age was 35.48 ± 1.20 weeks in the KMC group and 35.04 ± 1.09 weeks in the control group ( P > 0.05). KMC was initiated at a mean age of 1.72 ± 0.45 days and the duration of KMC was 9.74 ± 1.48 h/day. The mean birth weight was 1.69 ± 0.11 kg in the KMC group compared to 1.69 ± 0.12 kg in the control group ( P > 0.05). The mean weight gain in gm/day in the KMC group was 21.92 ± 1.44 compared to 18.61 ± 1.28 in the control group ( P < 0.05). The mean length gain in cm/week was 1.03 ± 0.5 in the KMC group compared to 0.74 ± 0.05 in the control group ( P < 0.05). The mean OFC gain in cm/week was 0.59 ± 0.04 in the KMC group compared to 0.47 ± 0.03 in the control group ( P < 0.05). The exclusive breast-feeding rate at end of three months was 88% in the KMC group compared to 72% in the control group ( P < 0.05). KMC improved physical growth, breastfeeding rates and was well accepted by both mothers and nursing staff.
Book Reviews
Authors: Lev Benjamin
Published: July 2010

In Book Reviews, we review an extensive and diverse range of books. They cover theory and applications in operations research, statistics, management science, econometrics, mathematics, computers, and information systems. In addition, we include books in other fields that emphasize technical applications. However, we do not review software. To submit a book for review, please send it to me at the above address. Although we cannot review all books because of space limitations, we do list all books that we receive. We commission all book reviews and do not accept unsolicited reviews. To become a reviewer, please send me your name, address, and specific areas of expertise. We encourage readers to suggest books for review or to ask publishers to send copies of such books.

The authors or editors of books that we review in this issue are Louis Anthony Cox Jr., Glenn H. Hurlbert, and Prescott C. Ensign.
Stewardship or Agency? A Social Embeddedness Reconciliation of Conduct and Performance in Public Family Businesses
Authors: Le Breton-Miller Isabelle , Miller Danny , Lester Richard H.
Published: July 2010

Two contradictory perspectives of family business conduct and performance are prominent in the literature. The stewardship perspective argues that family business owners and managers will act as farsighted stewards of their companies, investing generously in the business to enhance value for all stakeholders. By contrast, the agency and behavioral agency perspectives maintain that major family owners, in catering to family self-interest, will underinvest in the firm, avoid risk, and extract resources. This paper argues that both these views have application but under different circumstances, determined in part by the degree to which the firm and its executive actors are embedded within the family and thus identify with its interests. Stewardship behavior will be less common, and agency behavior will be more common the greater the number of family directors, officers, generations, and votes, and the more executives are susceptible to family influence. These findings are supported among Fortune 1000 firms, as well as among the subsample of those firms that are family businesses.
Family and gender values in contemporary Europe: The attitudinal gender gap from a cross-national perspective
Authors: Aboim Sofia
Published: July 2010

Drawing on data from the International Social Survey Programme 2002 survey Family and changing gender roles, this article looks at the diversity in attitudes towards gender relations and family values in contemporary Europe from a gender perspective. Rather than the idea of a one-dimensional move from tradition to modernity that would gradually erase the attitudinal gender gap, the findings corroborate that gender differentiation plays a key role in attitudinal patterns. Furthermore, the attitudinal gender gap is path-specific and varies according to country-specific societal modernisation. Hence, I examine differences in the statements of men and women to portray attitudinal gender gaps on the national level. I follow the idea that wide gender gaps are associated either with women's financial autonomy or with greater societal equality in education and political participation, since they allow for greater female awareness of masculine domination. I also argue that family deinstitutionalisation also correlates with greater attitudinal gender gaps.
Social insertion and racial prejudice: Distance from black people and socio-political variables
Authors: de Lima Nunes Aline Vieira , Lins Samuel Lincoln Bezerra , Camino Leoncio , Torres Ana Raquel Rosas
Published: July 2010

This article analyses the relationships between racial prejudice (flagrant and symbolic) and university students' membership of socio-political groups, their adhesion to political ideologies, and their attitudes related to the developed and developing worlds. A total of 418 students participated in the study. The results show a negative correlation between adhesion to left-wing ideology and social distance from black people. They also show that favourable attitudes to the developed world are positively correlated to the distance from black people. Finally, group memberships in social movements and in affective-religious communities inhibit the expression of symbolic racial prejudice.
Observed, unknown distributions of clinical chemical quantities should be considered to be log-normal: a proposal
Authors: Haeckel Rainer , Wosniok Werner
Published: July 2010

The distribution of many quantities in laboratory medicine are considered to be Gaussian if they are symmetric, although, theoretically, a Gaussian distribution is not plausible for quantities that can attain only non-negative values. If a distribution is skewed, further specification of the type is required, which may be difficult to provide. Skewed (non-Gaussian) distributions found in clinical chemistry usually show only moderately large positive skewness (e.g., log-normal- and χ2distribution). The degree of skewness depends on the magnitude of the empirical biological variation (CVe), as demonstrated using the log-normal distribution. A Gaussian distribution with a small CVe(e.g., for plasma sodium) is very similar to a log-normal distribution with the same CVe. In contrast, a relatively large CVe(e.g., plasma aspartate aminotransferase) leads to distinct differences between a Gaussian and a log-normal distribution. If the type of an empirical distribution is unknown, it is proposed that a log-normal distribution be assumed in such cases. This avoids distributional assumptions that are not plausible and does not contradict the observation that distributions with small biological variation look very similar to a Gaussian distribution.

Clin Chem Lab Med 2010;48:1393–6.
Automated reticulocyte counting: state of the art and clinical applications in the evaluation of erythropoiesis
Authors: Piva Elisa , Brugnara Carlo , Chiandetti Lino , Plebani Mario
Published: July 2010

The reticulocyte count reflects the erythropoietic activity of the bone marrow and is thus useful in both the diagnosis of anemias and in monitoring bone marrow response to therapy. Starting in the mid-1990s, automated flow-cytometric analysis has replaced traditional microscopic quantitation of reticulocytes. Reticulocyte analysis now includes measurements mRNA content and the maturity of reticulocytes, cell volume, hemoglobin concentration and content. The immature reticulocyte fraction is a reliable early predictor of hematopoietic engraftment following allogeneic stem cell transplantation, while the reticulocyte hemoglobin content provides an indirect measure of the functional iron available for new red blood cell production over the previous 3–4 days. Especially in anemic newborns, reticulocyte analysis is useful to help clinicians follow erythropoietic changes, to monitor response to recombinant human erythropoietin therapy, to gauge transfusion needs, and to evaluate jaundice. Despite improved accuracy and precision, significant problems still persist in maintaining adequate levels of precision and comparability across different laboratories. In the absence of better laboratory standardization, having a single reference range for the parameters provided by flow-cytometric studies of reticulocytes remains problematic.

Clin Chem Lab Med 2010;48:1369–80.
Observation of cell shapes in wood cross-sections during water adsorption by confocal laser-scanning microscopy (CLSM)
Authors: Taguchi Ayako , Murata Koji , Nakano Takato
Published: July 2010

Deformation behaviors of cell cross-sections from wood blocks were observed during water adsorption by confocal laser-scanning microscopy. In the tangential (T) direction, cells swelled linearly with increasing moisture content, whereas in the radial (R) direction, cell deformation varied from cell to cell, and some cells showed even shrinkage. This confirms that the well-known swelling/shrinking anisotropy for intact wood blocks is T>R.
A single cell model for pretreatment of wood by microwave explosion
Authors: Li Xianjun , Zhou Yongdong , Yan Yonglin , Cai Zhiyong , Feng Fu
Published: July 2010

A theoretical model was developed to better understand the process of microwave explosion treatment of wood cells. The cell expansion and critical conditions concerning pressure and temperature of ray parenchyma cells in Eucalyptus urophylla were simulated during microwave pretreatment. The results indicate that longitudinal and circumferential stresses were generated in the cell walls owing to the internal steam pressure during extensive microwave treatment. The circumferential stress is twice as high as the longitudinal stress. The pressure difference reaches its maximum value of 0.84 MPa when the extension ratio is 1.20 for the longitudinal direction and 1.62 for the circumferential direction. The maximum pressure difference at the theoretical yielding point is the critical pressure difference that can eventually rupture the ray cell. The critical pressure difference decreases with increasing cell radius and decreasing shear modulus in the cell wall. This simulated result provides useful information to modify wood at the level of ray parenchyma cells.
Macro- and micromechanical characterization of wood-adhesive bonds exposed to alternating climate conditions
Authors: Follrich Jürgen , Stöckel Frank , Konnerth Johannes
Published: July 2010

Three-part specimens were produced from Norway spruce wood (Picea abiesKarst.) and bonded with the following adhesives: melamine-urea-formaldehyde (MUF), phenol-resorcinol-formaldehyde (PRF), and a two-component emulsion polymer isocyanate (EPI). The effect of alternating climate conditions on bond strength was studied by tensile tests. The specimens were exposed to a three-step ageing cycle lasting for 7 days [50°C/95% relative humidity (RH), -20°C/65– 70% RH and 75°C/15% RH] which was repeated 24 times. In general, a decrease in internal bond strength of all exposed specimens was observed but it was highest in the case of MUF-bonded joints. Furthermore, a significant decrease of the tensile strength of the wood adherend perpendicular to the grain in the tangential direction was determined after the cyclic climatic changes. The mechanical performance of the different adhesives in the bond line was tested by means of nanoindentation. Reduced values of elastic modulus, hardness, and total indentation were observed after climatic treatment, particularly for the rigid MUF adhesive, whereas the flexible adhesive EPI did not show such changes.
Pore space analysis of beech wood: The vessel network
Authors: Hass Philipp , Wittel Falk K. , McDonald Sam A. , Marone Federica , Stampanoni Marco , Herrmann Hans J. , Niemz Peter
Published: July 2010

Water transport in wood is vital for the survival of trees. With synchrotron radiation X-ray tomographic microscopy (SRXTM), it has become possible to characterize and quantify the three-dimensional (3D) network formed by vessels that are responsible for longitudinal transport. In the present study, the spatial size dependence of vessels and the organization inside single growth rings in terms of vessel-induced porosity was studied by SRXTM. Network characteristics, such as connectivity, were deduced by digital image analysis from the processed tomographic data and related to known complex network topologies.
Learning-Associated Gamma-Band Phase-Locking of Action–Outcome Selective Neurons in Orbitofrontal Cortex
Authors: van Wingerden Marijn , Vinck Martin , Lankelma Jan V. , Pennartz Cyriel M. A.
Published: July 2010

Gamma oscillations (30–100 Hz) correlate to a variety of neural functions, including sensory processing, attention, and action selection. However, they have barely been studied in relation to emotional processing and valuation of sensory signals and actions. We conducted multineuron and local field potential recordings in the orbitofrontal cortex (OFC) of rats performing a task in which they made go or no-go decisions based on two olfactory stimuli predicting appetitive or aversive outcomes.

Gamma power was strongest during the late phase of odor sampling, just before go/no-go movement, and increased with behavioral learning. Learning speed was correlated to the slope of the gamma power increment. Spikes of OFC neurons were consistently timed to the gamma rhythm during odor sampling, regardless of the associated outcome. However, only a specific subgroup of cells showed consistent phase timing. These cells showed action–outcome selective activity, not during stimulus sampling but during subsequent movement responses. During sampling, this subgroup displayed a suppression in firing rate but a concurrent increment in the consistency of spike timing relative to gamma oscillations.

In addition to gamma rhythm, OFC field potentials were characterized by theta oscillations during odor sampling. Neurons phase-locked to either theta or gamma rhythms but not to both, suggesting that they become associated with separate rhythmic networks involving OFC. Altogether, these results suggest that OFC gamma-band synchronization reflects inhibitory control over a subpopulation of neurons that express information about the emotional valence of actions after a motor decision, which suggests a novel mechanism for response inhibition.
EngrailedHomeobox Genes Regulate Establishment of the Cerebellar Afferent Circuit Map
Authors: Sillitoe Roy V. , Vogel Michael W. , Joyner Alexandra L.
Published: July 2010

The spatial organization of the cerebellar afferent map has remarkable correspondence to two aspects of intrinsic patterning within the cerebellum embodied by a series of lobules and Purkinje cell (PC)-striped gene expression. Using male and female mice, we tested whether theEngrailed(En) homeobox genes are a common genetic substrate regulating all three systems, since they are expressed in spatially restricted domains within the cerebellum and are critical for patterning PC gene expression and foliation. Indeed, we discovered thatEn1/2are necessary for the precise targeting of mossy fibers to distinct lobules, as well as their subsequent resolution into discrete parasagittal bands. Moreover, eachEngene coordinately regulates afferent targeting and the striped pattern of PC protein expression (e.g., ZebrinII/AldolaseC) independent of regulating foliation. We further found thatEn1/2, rather than the presence of a full complement of lobules, are critical for generating PC protein stripes and mossy fiber bands, and that PC striped gene expression is determined before afferent banding. Thus, theEntranscription factors not only regulate cerebellum circuit topography, but they also link afferent and efferent neurons precisely enough that alterations in PC protein expression can be used as a read out for underlying defects in circuitry. In summary, our data suggest thatEn1/2are master regulators of three-dimensional organization of the cerebellum and coordinately regulate morphology, patterned gene expression, and afferent topography.
Activation of α4* nAChRs is Necessary and Sufficient for Varenicline-Induced Reduction of Alcohol Consumption
Authors: Hendrickson Linzy M. , Zhao-Shea Rubing , Pang Xueyan , Gardner Paul D. , Tapper Andrew R.
Published: July 2010

Recently, the smoking cessation therapeutic varenicline, a nicotinic acetylcholine receptor (nAChR) partial agonist, has been shown to reduce alcohol consumption. However, the mechanism and nAChR subtype(s) involved are unknown. Here we demonstrate that varenicline and alcohol exposure, either alone or in combination, selectively activates dopaminergic (DAergic) neurons within the posterior, but not the anterior, ventral tegmental area (VTA). To gain insight into which nAChR subtypes may be involved in the response to alcohol, we analyzed nAChR subunit gene expression in posterior VTA DAergic neurons. Ethanol-activated DAergic neurons expressed higher levels of α4, α6, and β3 subunit genes compared with nonactivated neurons. To examine the role of nicotinic receptors containing the α4 subunit (α4* nAChRs) in varenicline-induced reduction of alcohol consumption, we examined the effect of the drug in two complementary mouse models, a knock-out line that does not express the α4 subunit (α4 KO) and another line that expresses α4* nAChRs hypersensitive to agonist (Leu9′Ala). While varenicline (0.1–0.3 mg/kg, i.p.) reduced 2% and 20% alcohol consumption in wild-type (WT) mice, the drug did not significantly reduce consumption in α4 KO animals. Conversely, low doses of varenicline (0.0125–0.05 mg/kg, i.p.) that had little effect in WT mice dramatically reduced ethanol intake in Leu9′Ala mice. Infusion of varenicline into the posterior, but not the anterior VTA was sufficient to reduce alcohol consumption. Together, our data indicate that activation of α4* nAChRs is necessary and sufficient for varenicline reduction of alcohol consumption.
Multiple Mechanisms of Consciousness: The Neural Correlates of Emotional Awareness
Authors: Amting Jayna M. , Greening Steven G. , Mitchell Derek G. V.
Published: July 2010

Emotional stimuli, including facial expressions, are thought to gain rapid and privileged access to processing resources in the brain. Despite this access, we are conscious of only a fraction of the myriad of emotion-related cues we face everyday. It remains unclear, therefore, what the relationship is between activity in neural regions associated with emotional representation and the phenomenological experience of emotional awareness. We used functional magnetic resonance imaging and binocular rivalry to delineate the neural correlates of awareness of conflicting emotional expressions in humans. Behaviorally, fearful faces were significantly more likely to be perceived than disgusted or neutral faces. Functionally, increased activity was observed in regions associated with facial expression processing, including the amygdala and fusiform gyrus during emotional awareness. In contrast, awareness of neutral faces and suppression of fearful faces were associated with increased activity in dorsolateral prefrontal and inferior parietal cortices. The amygdala showed increased functional connectivity with ventral visual system regions during fear awareness and increased connectivity with perigenual prefrontal cortex (pgPFC; Brodmann's area 32/10) when fear was suppressed. Despite being prioritized for awareness, emotional items were associated with reduced activity in areas considered critical for consciousness. Contributions to consciousness from bottom-up and top-down neural regions may be additive, such that increased activity in specialized regions within the extended ventral visual system may reduce demands on a frontoparietal system important for awareness. The possibility is raised that interactions between pgPFC and the amygdala, previously implicated in extinction, may also influence whether or not an emotional stimulus is accessible to consciousness.
Nelson's syndrome
Authors: Barber T M , Adams E , Ansorge O , Byrne J V , Karavitaki N , Wass J A H
Published: July 2010

Nelson's syndrome is a potentially life-threatening condition that does not infrequently develop following total bilateral adrenalectomy (TBA) for the treatment of Cushing's disease. In this review article, we discuss some controversial aspects of Nelson's syndrome including diagnosis, predictive factors, aetiology, pathology and management based on data from the existing literature and the experience of our own tertiary centre.

Definitive diagnostic criteria for Nelson's syndrome are lacking. We argue in favour of a new set of criteria. We propose that Nelson's syndrome should be diagnosed in any patient with prior TBA for the treatment of Cushing's disease and with at least one of the following criteria: i) an expanding pituitary mass lesion compared with pre-TBA images; ii) an elevated 0800 h plasma level of ACTH (>500 ng/l) in addition to progressive elevations of ACTH (a rise of >30%) on at least three consecutive occasions. Regarding predictive factors for the development of Nelson's syndrome post TBA, current evidence favours the presence of residual pituitary tumour on magnetic resonance imaging (MRI) post transsphenoidal surgery (TSS); an aggressive subtype of corticotrophinoma (based on MRI growth rapidity and histology of TSS samples); lack of prophylactic neoadjuvant pituitary radiotherapy at the time of TBA and a rapid rise of ACTH levels in year 1 post TBA. Finally, more studies are needed to assess the efficacy of therapeutic strategies in Nelson's syndrome, including the alkylating agent, temozolomide, which holds promise as a novel and effective therapeutic agent in the treatment of associated aggressive corticotroph tumours. It is timely to review these controversies and to suggest guidelines for future audit.
Seasonal Energetics and Condition of Bonefish from Different Subtropical Tidal Creeks in Eleuthera, the Bahamas
Authors: Murchie Karen J. , Cooke Steven J. , Danylchuk Andy J.
Published: July 2010

Body composition and fish health indices of bonefish Albula vulpes were investigated to elucidate the energy dynamics in poorly studied tropical tidal flat environments. In general, bonefish were composed of 72% water, 21% protein, 4% ash, and 3% lipids, which is consistent with the wet weight values of the majority of freshwater and marine fish studied to date. Significant inverse relationships between the water and lipid contents of whole-body, gonad, and liver tissues revealed that the percentage of water is a good indicator of the relative amount of stored energy in bonefish and may be used as a surrogate for lipid content in future studies. The liver was the main storage site for lipids, containing more than twice the fat in the whole body. While both abiotic (e.g., season and location) and biotic (e.g., sex and size) factors contributed to the predictive power of the general linear models generated for all constituent analyses, there were no significant differences in whole-body or liver lipid content between seasons, which may be explained by there being a consistent food supply year-round. There was, however, a significant relationship between lipid content and body size with respect to season. Lipid content decreased in the winter and increased in the summer with increasing body size, a trend that can be explained by the timing of the reproductive season in bonefish. Seasonal changes in the condition factor and gonadosomatic indices were also linked to the winter spawning season, with decreasing body condition and increasing gonad development in the winter. Observed site-specific differences in the lipid content and liver somatic indices of bonefish may be accounted for by local trophodynamics as well as subtle differences in life history strategies. The energy reserve and fish health index data collected in this study may provide a useful baseline for future comparative work and help elucidate fish energetics in dynamic tropical tidal flat systems.
Relações radiométricas no terço superior da copa de cafeeiro
Authors: Cunha Antonio Ribeiro da , Volpe Clovis Alberto
Published: July 2010

Com o objetivo de obter os coeficientes de transmissão e de extinção da radiação fotossinteticamente ativa determinou-se o índice de área foliar e mediu-se a radiação fotossinteticamente ativa transmitida no terço superior da copa de cafeeiro variedade Obatã IAC 1669-20, com três diferentes alinhamentos de plantio, em função da trajetória aparente do Sol, em Jaboticabal (SP). Foram três tratamentos, com quatro repetições, no total de doze parcelas, e cada uma com cem cafeeiros; cada tratamento correspondeu a um alinhamento de plantio. O alinhamento 81º-261º, por ser o que mais se aproximava do movimento aparente do Sol desde o nascente até o poente, favoreceu um autossombreamento maior na linha, e assim, ocorre maior disponibilidade de radiação solar difusa, contribuindo para maior índice de área foliar. Os coeficientes de transmissão são menores e os de atenuação são maiores para o alinhamento 81º-261º, revelando maior eficiência na interceptação da radiação fotossinteticamente ativa no terço superior da copa desse alinhamento. Foi possível estimar o coeficiente de extinção (kRFA) em função do índice de área foliar (IAF) por meio do modelo exponencial: κRFA = A + B* exp(-IAF/C); e estimar o índice de área foliar em função da radiação fotossinteticamente ativa interceptada (RFAint) pelo modelo polinomial quadrático: IAF = A(RFAint)² + B(RFAint) + C, onde A, B e C são parâmetros dos modelos.
Manejo integrado de plantas daninhas na cultura do milho
Authors: Nunes Anderson Luis , Trezzi Michelangelo Muzell , Debastiani Clenio
Published: July 2010

Estratégia de manejo de plantas daninhas pode ser realizada de forma integrada com o método químico na redução da utilização de herbicidas na cultura do milho. O objetivo deste trabalho é avaliar o efeito do manejo integrado do espaçamento entre linhas, ou de híbridos de milho com características morfológicas distintas e redução dos níveis de herbicidas, para controlar plantas daninhas na cultura do milho. O experimento foi instalado em delineamento de blocos ao acaso, com quatro repetições, arranjado em um fatorial 2 x 2 x 5, em que: o primeiro fator foram os híbridos Penta (superprecoce, com folhas mais planas) e Flash (superprecoce com folhas mais eretas); o segundo fator foram os espaçamentos entre linhas de milho (0,45 e 0,9 m) e o terceiro fator os níveis de manejo de plantas daninhas (capinado, sem capina e atrazine + foramsulfurom + iodosulfuron nas doses de 3000+45+3, 2250+33,8+2,3 e 1500+22,5+1,5 g ha-1 i.a.). Foram avaliados a altura e o ângulo foliar vertical das plantas, o número de plantas daninhas e a matéria seca de plantas daninhas por área. O ângulo foliar de plantas de milho torna-se mais planófilo com a adoção de espaçamentos reduzidos entre linhas, mas outras características de plantas de milho estão envolvidas no desempenho dos espaçamentos. O uso do espaçamento de 0,45 m entre linhas não contribui para a redução dos níveis de herbicidas para a cultura, mas sua adoção beneficia o manejo de plantas daninhas e o rendimento de grãos do híbrido Flash, embora não seja vantajosa para o híbrido Penta.
Effects of coloured shade netting on the vegetative development and leaf structure of Ocimum selloi
Authors: Costa Larissa Corrêa do Bomfim , Pinto José Eduardo Brasil Pereira , Castro Evaristo Mauro de , Alves Eduardo , Bertolucci Suzan Kelly Vilela , Rosal Louise Ferreira
Published: July 2010

The objective of this work was to investigate the effects of shading on the growth and development of the medicinal plant Ocimum selloi after 90 days. Seedlings were maintained under three different light treatments, namely, full sunlight vs coloured shade treatments provided by red and blue ChromatiNet® 50% coloured netting. After 90 days of cultivation, height, stem diameter, petiole length, total leaf area (TLA), specific leaf area (SLA), leaf area ratio (LAR) and leaf weight ratio (LWR) of each plant hare measured. Microscopic examination of leaf sections were conducted in order to determine the leaf blade thicknesses, together with the size and density of the stomata, the number and area of chloroplasts, and chloroplast starch grains present in the palisade parenchyma cells. Although coloured shade-grown plants were taller in comparison with those grown in full sunlight, total dry biomass together with root, stem and leaf tissue biomasses were lower. Plants exhibited phenotypic plasticity, as demonstrated by the different TLA, SLA, LAR and LWR values that were recorded under the various light treatments. Stomatal density and leaf thickness was increased in plants maintained in full sunlight owing to the expansion of the abaxial epidermis and the spongy parenchyma. Chloroplasts were more numerous and larger in plants grown under shading, whilst the accumulation of chloroplastic starch grains was greater in plants grown under red shading or in full sunlight.