bluuebunny/crossref_metadata_2025 huggingface dataset:
Perspectives on quality of experience for video streaming over WiMAX
Authors: Vishwanath Arun , Dutta Partha , Chetlu Malolan , Gupta Parul , Kalyanaraman Shivkumar , Ghosh Amitabha
Published: March 2010

The advent of broadband wireless networks, such as WiMAX, is paving the way for the widespread deployment of high-bandwidth video streaming services for mobile users. To provide acceptable end-to-end performance in such a network, it is important to monitor the Quality of Experience (QoE) of the user, since the inherent variability in the wireless channel can undermine the video quality significantly. In this context, this paper undertakes a simulation study to evaluate the user's QoE (using PSNR as the representative metric) when video is streamed from a source to a Mobile Station (MS) via a WiMAX Base Station (BS). The WiMAX Forum's ns-2 simulator is used to carry out all the simulations. In particular, we explore the impact of the following parameters, namely, (1) the reserved rate at the BS for the video stream, (2) the Modulation and Coding Scheme employed, (3) the distance between BS and MS, and (4) the tolerable end-to-end delay, on the QoE. Our results point to various trade-offs that exist among these parameters, which can be effectively used to manage the user's viewing experience under varying channel conditions and resource constraints.
WiPal
Authors: Claveirole Thomas , Dias de Amorim Marcelo
Published: March 2010

Merging wireless traces is a fundamental step in measurement-based studies involving multiple packet sniffers. Existing merging tools either require a wired infrastructure or are limited in their usability. We propose WiPal, an offline merging tool for IEEE 802.11 traces that has been designed to be efficient and simple to use. WiPal is flexible in the sense that it does not require any specific services, neither from monitors (like synchronization, access to a wired network, or embedding specific software) nor from its software environment (e.g., an SQL server). WiPal is available for download as free software.

In this article, we present WiPal's design and algorithms. Most notably we propose a new synchronization algorithm that uses linear regressions on sliding windows of reference frames. A study of this algorithm shows it performs better than other synchronization algorithms. Experiments on real traces also show thatWiPal is an order of magnitude faster than other tools providing the same features.
Differentiation of Effector CD4 T Cell Populations
Authors: Zhu Jinfang , Yamane Hidehiro , Paul William E.
Published: March 2010

CD4 T cells play critical roles in mediating adaptive immunity to a variety of pathogens. They are also involved in autoimmunity, asthma, and allergic responses as well as in tumor immunity. During TCR activation in a particular cytokine milieu, naive CD4 T cells may differentiate into one of several lineages of T helper (Th) cells, including Th1, Th2, Th17, and iTreg, as defined by their pattern of cytokine production and function. In this review, we summarize the discovery, functions, and relationships among Th cells; the cytokine and signaling requirements for their development; the networks of transcription factors involved in their differentiation; the epigenetic regulation of their key cytokines and transcription factors; and human diseases involving defective CD4 T cell differentiation.
Inflammatory Bowel Disease
Authors: Kaser Arthur , Zeissig Sebastian , Blumberg Richard S.
Published: March 2010

Insights into inflammatory bowel disease (IBD) are advancing rapidly owing to immunologic investigations of a plethora of animal models of intestinal inflammation, ground-breaking advances in the interrogation of diseases that are inherited as complex genetic traits, and the development of culture-independent methods to define the composition of the intestinal microbiota. These advances are bringing a deeper understanding to the genetically determined interplay between the commensal microbiota, intestinal epithelial cells, and the immune system and the manner in which this interplay might be modified by relevant environmental factors in the pathogenesis of IBD. This review examines these interactions and, where possible, potential lessons from IBD-directed, biologic therapies that may allow for elucidation of pathways that are central to disease pathogenesis in humans.
Control of Immunity by the TNFR-Related Molecule OX40 (CD134)
Authors: Croft Michael
Published: March 2010

TNFR/TNF superfamily members can control diverse aspects of immune function. Research over the past 10 years has shown that one of the most important and prominent interactions in this family is that between OX40 (CD134) and its partner OX40L (CD252). These molecules strongly regulate conventional CD4 and CD8 T cells, and more recent data are highlighting their ability to modulate NKT cell and NK cell function as well as to mediate cross-talk with professional antigen-presenting cells and diverse cell types such as mast cells, smooth muscle cells, and endothelial cells. Additionally, OX40-OX40L interactions alter the differentiation and activity of regulatory T cells. Blocking OX40L has produced strong therapeutic effects in multiple animal models of autoimmune and inflammatory disease, and, in line with a prospective clinical future, reagents that stimulate OX40 signaling are showing promise as adjuvants for vaccination as well as for treatment of cancer.
On the Composition of the Preimmune Repertoire of T Cells Specific for Peptide–Major Histocompatibility Complex Ligands
Authors: Jenkins Marc K. , Chu H. Hamlet , McLachlan James B. , Moon James J.
Published: March 2010

Millions of T cells are produced in the thymus, each expressing a unique α/β T cell receptor (TCR) capable of binding to a foreign peptide in the binding groove of a host major histocompatibility complex (MHC) molecule. T cell–mediated immunity to infection is due to the proliferation and differentiation of rare clones in the preimmune repertoire that by chance express TCRs specific for peptide-MHC (pMHC) ligands derived from the microorganism. Here we review recent findings that have altered our understanding of how the preimmune repertoire is established. Recent structural studies indicate that a germline-encoded tendency of TCRs to bind MHC molecules contributes to the MHC bias of T cell repertoires. It has also become clear that the preimmune repertoire contains functionally heterogeneous subsets including recent thymic emigrants, mature naive phenotype cells, memory phenotype cells, and natural regulatory T cells. In addition, sensitive new detection methods have revealed that the repertoire of naive phenotype T cells consists of distinct pMHC-specific populations that consistently vary in size in different individuals. The implications of these new findings for the clonal selection theory, self-tolerance, and immunodominance are discussed.
The Role of Antibodies in HIV Vaccines
Authors: Mascola John R. , Montefiori David C.
Published: March 2010

Licensed vaccines against viral diseases generate antibodies that neutralize the infecting virus and protect against infection or disease. Similarly, an effective vaccine against HIV-1 will likely need to induce antibodies that prevent initial infection of host cells or that limit early events of viral dissemination. Such antibodies must target the surface envelope glycoproteins of HIV-1, which are highly variable in sequence and structure. The first subunit vaccines to enter clinical trails were safe and immunogenic but unable to elicit antibodies that neutralized most circulating strains of HIV-1. However, potent virus neutralizing antibodies (NAbs) can develop during the course of HIV-1 infection, and this is the type of antibody response that researchers seek to generate with a vaccine. Thus, current vaccine design efforts have focused on a more detailed understanding of these broadly neutralizing antibodies and their epitopes to inform the design of improved vaccines.
The Sterile Inflammatory Response
Authors: Rock Kenneth L. , Latz Eicke , Ontiveros Fernando , Kono Hajime
Published: March 2010

The acute inflammatory response is a double-edged sword. On the one hand, it plays a key role in initial host defense, particularly against many infections. On the other hand, its aim is imprecise, and as a consequence, when it is drawn into battle, it can cause collateral damage in tissues. In situations where the inciting stimulus is sterile, the cost-benefit ratio may be high; because of this, sterile inflammation underlies the pathogenesis of a number of diseases. Although there have been major advances in our understanding of how microbes trigger inflammation, much less has been learned about this process in sterile situations. This review focuses on a subset of the many sterile stimuli that can induce inflammation—specifically dead cells and a variety of irritant particles, including crystals, minerals, and protein aggregates. Although this subset of stimuli is structurally very diverse and might appear to be unrelated, there is accumulating evidence that the innate immune system may recognize them in similar ways and stimulate the sterile inflammatory response via common pathways. Here we review established and emerging data about these responses.
Adaptive Immune Regulation in the Gut: T Cell–Dependent and T Cell–Independent IgA Synthesis
Authors: Fagarasan Sidonia , Kawamoto Shimpei , Kanagawa Osami , Suzuki Keiichiro
Published: March 2010

In mammals, the gastrointestinal tract harbors an extraordinarily dense and complex community of microorganisms. The gut microbiota provide strong selective pressure to the host to evolve adaptive immune responses required for the maintenance of local and systemic homeostasis. The continuous antigenic presence in the gut imposes a dynamic remodeling of gut-associated lymphoid tissues (GALT) and the selection of multiple layered strategies for immunoglobulin (Ig) A production. The composite and dynamic gut environment also necessitates heterogeneous, versatile, and convertible T cells, capable of inhibiting (Foxp3+T cells) or helping (TFHcells) local immune responses. In this review, we describe recent advances in our understanding of dynamic pathways that lead to IgA synthesis, in gut follicular structures and in extrafollicular sites, by T cell–dependent and T cell–independent mechanisms. We discuss the finely tuned regulatory mechanisms for IgA production and emphasize the role of mucosal IgA in the selection and maintenance of the appropriate microbial composition that is necessary for immune homeostasis.
Molecular Basis of Calcium Signaling in Lymphocytes: STIM and ORAI
Authors: Hogan Patrick G. , Lewis Richard S. , Rao Anjana
Published: March 2010

Ca2+entry into cells of the peripheral immune system occurs through highly Ca2+-selective channels known as CRAC (calcium release-activated calcium) channels. CRAC channels are a very well-characterized example of store-operated Ca2+channels, so designated because they open when the endoplasmic reticulum (ER) Ca2+store becomes depleted. Physiologically, Ca2+is released from the ER lumen into the cytoplasm when activated receptors couple to phospholipase C and trigger production of the second messenger inositol 1,4,5-trisphosphate (IP3). IP3binds to IP3receptors in the ER membrane and activates Ca2+release. The proteins STIM and ORAI were discovered through limited and genome-wide RNAi screens, respectively, performed in Drosophila cells and focused on identifying modulators of store-operated Ca2+entry. STIM1 and STIM2 sense the depletion of ER Ca2+stores, whereas ORAI1 is a pore subunit of the CRAC channel. In this review, we discuss selected aspects of Ca2+signaling in cells of the immune system, focusing on the roles of STIM and ORAI proteins in store-operated Ca2+entry.
Onset of obesity in carboxypeptidase E-deficient mice and effect on airway responsiveness and pulmonary responses to ozone
Authors: Johnston Richard A. , Zhu Ming , Hernandez Christopher B. , Williams Erin S. , Shore Stephanie A.
Published: March 2010

When compared with lean, wild-type mice, obese Cpefatmice, 14 wk of age and older, manifest innate airway hyperresponsiveness (AHR) to intravenous methacholine and enhanced pulmonary inflammation following acute exposure to ozone (O3). The purpose of this study was to examine the onset of these augmented pulmonary responses during the onset of obesity. Thus airway responsiveness and O3-induced pulmonary inflammation and injury were examined in 7- and 10-wk-old Cpefatand age-matched, wild-type, C57BL/6 mice. Compared with age-matched controls, 7- and 10-wk-old Cpefatmice were approximately 25 and 61% heavier, respectively. Airway responsiveness to intravenous methacholine was assessed via forced oscillation in unexposed Cpefatand wild-type mice. The 10- but not 7-wk-old Cpefatmice exhibited innate AHR. O3exposure (2 ppm for 3 h) increased markers of pulmonary inflammation and injury in the bronchoalveolar lavage fluid of all mice. However, most markers were greater in Cpefatvs. wild-type mice, regardless of age. Serum levels of leptin, a satiety hormone and proinflammatory cytokine, were increased in Cpefatvs. wild-type mice of both age groups, but the serum levels of other systemic inflammatory markers were greater only in 10-wk-old Cpefatvs. wild-type mice. These results demonstrate that a 25% increase in body weight is sufficient to augment pulmonary responses to O3, but innate AHR is not manifest until the mice become much heavier. These results suggest that the mechanistic bases for these responses are different and may develop according to the nature and degree of the chronic systemic inflammation that is present.
Theoretical Study of a Chain Sliding on a Fixed Support
Authors: Bastien Jérôme , Lamarque Claude-Henri
Published: March 2010

A chain sliding on a fixed support, made out of some elementary rheological models (dry friction element and linear spring) can be covered by the existence and uniqueness theory for maximal monotone operators. Several behavior from quasistatic to dynamical are investigated. Moreover, classical results of numerical analysis allow to use a numerical implicit Euler scheme.
Neonatal Outcomes of Late‐Preterm Birth Associated or Not with Intrauterine Growth Restriction
Authors: Ortigosa Rocha Cristiane , Bittar Roberto Eduardo , Zugaib Marcelo
Published: March 2010

Objective. To compare neonatal morbidity and mortality between late‐preterm intrauterine growth‐restricted (IUGR) and appropriate‐for‐gestational‐age (AGA) infants of the comparable gestational ages (GAs). Methods. We retrospectively analyzed neonatal morbidity and mortality of 50 singleton pregnancies involving fetuses with IUGR delivered between 34 and 36 6/7 weeks of GA due to maternal and/or fetal indication. The control group consisted of 36 singleton pregnancies with spontaneous preterm delivery at the same GA, in which the infant was AGA. Categorical data were compared between IUGR and AGA pregnancies by X2 analysis and Fisher′s exact test. Ordinal measures were compared using the Kruskal‐Wallis test. Results. The length of stay of newborns in the nursery, as well as the need for and duration of hospitalization in the neonatal intensive care unit, was longer in the group with IUGR. Transient tachypnea of the newborn or apnea rates did not differ significantly between the IUGR and AGA groups. IUGR infants were found to be at a higher risk of intraventricular hemorrhage. No respiratory distress syndrome, pulmonary hemorrhage or bronchopulmonary dysplasia was observed in either group. The frequency of sepsis, thrombocytopenia and hyperbilirubinemia was similar in the two groups. Hypoglycemia was more frequent in the IUGR group. No neonatal death was observed. Conclusion. Our study showed that late‐preterm IUGR infants present a significantly higher risk of neonatal complications when compared to late‐preterm AGA infants.
Popliteal Artery Entrapment Syndrome Presenting with Acute Limb Ischaemia: A Case Report
Authors: Soobrah Ramawad , Nawaz Adam , Hussain Tahir
Published: March 2010

Popliteal artery entrapment syndrome (PAES) is a relatively rare condition that occurs in young patients as a result of anomalous anatomic relationships between the popliteal artery and the surrounding musculotendinous structures. Patients usually lack atherogenic risk factors and most commonly present with intermittent claudication in the early stages. In the later stages of undiagnosed PAES, acute ischaemia can occur as a result of complete arterial occlusion or embolism. Hence, early diagnosis and surgical release of the entrapment is crucial for good operative outcome and to prevent limb loss.
Novel Approaches to Treat Experimental Pulmonary Arterial Hypertension: A Review
Authors: Umar S. , Steendijk P. , Ypey D. L. , Atsma D. E. , van der Wall E. E. , Schalij M. J. , van der Laarse A.
Published: March 2010

Background. Pulmonary arterial hypertension (PAH) is a life-threatening disease characterized by an increase in pulmonary artery pressure leading to right ventricular (RV) hypertrophy, RV failure, and ultimately death. Current treatments can improve symptoms and reduce severity of the hemodynamic disorder but gradual deterioration in their condition often necessitates a lung transplant.Methods and Results. In experimental models of PAH, particularly the model of monocrotaline-induced pulmonary hypertension, efficacious treatment options tested so far include a spectrum of pharmacologic agents with actions such as anti-mitogenic, proendothelial function, proangiogenic, antiinflammatory and antioxidative. Emerging trends in PAH treatment are gene and cell therapy and their combination, like (progenitor) cells enriched with eNOS or VEGF gene. More animal data should be collected to investigate optimal cell type, in vitro cell transduction, route of administration, and number of cells to inject. Several recently discovered and experimentally tested interventions bear potential for therapeutic purposes in humans or have been shown already to be effective in PAH patients leading to improved life expectation and better quality of life.Conclusion. Since many patients remain symptomatic despite therapy, we should encourage research in animal models of PAH and implement promising treatments in homogeneous groups of PAH patients.
Effects of Exogenous Corticosterone on Circulating Leukocytes of a Salamander (Ambystoma talpoideum) with Unusually Abundant Eosinophils
Authors: Davis Andrew K. , Maerz John C.
Published: March 2010

When animals become stressed, their levels of glucocorticoid hormones increase, causing white blood cells to move from tissues to circulation or vice versa. The primary alteration is an increase in the abundance of circulating neutrophils and a decrease in lymphocytes in circulation. A lesser-known effect is a decrease in the number of circulating eosinophils. Salamanders in the genusAmbystomahave unusually high numbers of circulating eosinophils, and as such, any effect of stress hormones on circulating leukocytes (especially eosinophils) of these species should be especially pronounced. We conducted an experiment to determine the effect of corticosterone administration on leukocyte counts (from blood smears) ofA. talpoideumsalamanders. Salamanders were captured and sampled as reference animals(n=11), given a sham injection(n=8), or injected with 0.1cc of a 100 μg/mL corticosterone solution(n=28). After 24 hours, relative neutrophil counts were higher and relative lymphocyte counts lower, in the corticosterone group than the sham and control groups. Absolute counts showed that this effect was driven by a reduction in lymphocytes, since neutrophil counts were statistically similar across treatments. Importantly, relative and absolute numbers of eosinophils decreased in the sham and corticosterone groups, confirming the sensitivity of this cell to stress in amphibians.
Can We Predict How Earthworm Effects on Plant Growth Vary with Soil Properties?
Authors: Laossi Kam-Rigne , Decaëns Thibaud , Jouquet Pascal , Barot Sébastien
Published: March 2010

Earthworms are usually assumed to enhance plant growth through different mechanisms which are now clearly identified. It is however difficult to determine their relative importance, and to predict a priori the strength and direction of the effects of a given earthworm species on a given plant. Soil properties are likely to be very influential in determining plant responses to earthworm activities. They are likely to change the relative strength of the various mechanisms involved in plant-earthworm interactions. In this paper, we review the different rationales used to explain changes in earthworm effect due to soil type. Then, we systematically discuss the effect of main soil characteristics (soil texture, OM, and nutrient contents) on the different mechanisms allowing earthworm to influence plant growth. Finally, we identify the main shortcomings in our knowledge and point out the new experimental and meta-analytical approaches that need to be developed. An example of such a meta-analysis is given and means to go further are suggested. The result highlights a strong positive effect size in sandy soil and a weakly negative effect in clayey soil.
A Video Browsing Tool for Content Management in Postproduction
Authors: Bailer Werner , Weiss Wolfgang , Kienast Gert , Thallinger Georg , Haas Werner
Published: March 2010

We propose an interactive video browsing tool for supporting content management and selection in postproduction. The approach is based on a process model for multimedia content abstraction. A software framework based on this process model and desktop and Web-based client applications are presented. For evaluation, we apply two TRECVID style fact finding approaches (retrieval and question answering tasks) and a user survey to the evaluation of the video browsing tool. We analyze the correlation between the results of the different methods, whether different aspects can be evaluated independently with the survey, and if a learning effect can be measured with the different methods, and we also compare the full-featured desktop and the limited Web-based user interface. The results show that the retrieval task correlates better with the user experience according to the survey. The survey rather measures the general user experience while different aspects of the usability cannot be analyzed independently.
Characterization of Recombinant Dengue-2 Virus Derived from a Single Nucleotide Substitution in the 5′ Noncoding Region
Authors: Leardkamolkarn Vijittra , Sirigulpanit Wipawan , Kinney Richard M.
Published: March 2010

Variants of wild-type dengue serotype 2 (DEN-2) virus containing nucleotide substitutions at positions 14, 15, or 57 in the5′NCR were constructed by PCR-mediated site-directed mutagenesis. All three viruses containing a single point substitution demonstrated attenuation phenotype as evidenced by decreases replication and plaque size in cell culture assay. All three variants were less neurovirulent in newborn mice compared to the wild type. The mutants were immunogenic in adult mice immunogenicity and maintained stable replication characteristics following passage in mice. The variant viruses were competent for replication inAedes aegypimosquito vector, albeit at lower levels of infection and dissemination in the mosquito than the wild-type Den-2 16681 virus. Although all of the viruses, including the wild type, were found transmissible in mosquito life cycles, they were found subsequentially decreased in efficiency of infection, transmission, and dissemination rates along the mosquito generations and all of them remained genetically stable.
JAK3/STAT5/6 Pathway Alterations Are Associated with Immune Deviation inCD8+T Cells in Renal Cell Carcinoma Patients
Authors: Cavalcanti Elisabetta , Gigante Margherita , Mancini Vito , Battaglia Michele , Ditonno Pasquale , Capobianco Carmela , Cincione Raffaele I. , Selvaggi Francesco P. , Herr Wolfgang , Storkus Walter J. , Gesualdo Loreto , Ranieri Elena
Published: March 2010

To investigate the molecular mechanisms underlying altered T cell response in renal cell carcinoma (RCC) patients, we compared autologous and allogeneicCD8+T cell responses against RCC line from RCC patients and their HLA-matched donors, using mixed lymphocyte/tumor cell cultures (MLTCs). In addition, we analyzed the expression of molecules associated with cell cycle regulation. Autologous MLTC responderCD8+T cells showed cytotoxic activity against RCC cell lines; however the analysis of the distribution ofCD8+T-cell subsets revealed that allogenic counterparts mediate superior antitumor efficacy. In RCC patients, a decreased proliferative response to tumor, associated with defects in JAK3/STAT5/6 expression that led to increased p27KIP1 expression and alterations in the cell cycle, was observed. These data define a molecular pathway involved in cell cycle regulation that is associated with the dysfunction of tumor-specificCD8+effector cells. If validated, this may define a therapeutic target in the setting of patients with RCC.
Lower Barthel Index Scores Predict Less Prescription of Pharmacological Therapy in Elderly Patients with Alzheimer Disease
Authors: Formiga Francesc , Fort Isabel , Robles Maria Jose , Rodriguez Daniel , Regalado Pedro
Published: March 2010

Aims: To determine the factors associated with receiving specific treatment (cholinesterase inhibitors or/and memantine) for Alzheimer disease (AD) in elderly patients. Methods: An observational study carried out in 289 consecutive outpatients aged >64 years with dementia. We collected data on specific AD therapy, sociodemographic variables, Barthel Index (BI), Lawton and Brody Index (LI), Mini Mental State Examination, Global Deterioration Scale (GDS), Charlson Index and the total number of drugs chronically prescribed. Patients receiving specific therapy for dementia were compared with the rest. Results: Two hundred and thirty-three (80.6%) patients were receiving specific treatment for dementia, with 197 (84.5%) receiving monotherapy and the rest (15.4%) combined therapy. The bivariate analysis showed that age, marital status, place of residence, BI and LI, cognitive status and disease severity (GDS) were factors associated with receiving specific dementia therapy. Multiple stepwise logistic regression analysis showed that a lower BI (β = –0.25; odds ratio 0.976, 95% confidence interval = 0.966–0.986; p < 0.0001) was the only factor independently associated with not receiving specific therapy for AD. Conclusions: Of the possible factors related to elderly patients receiving specific therapy for AD, a poor BI score was the most important factor associated with not receiving treatment.
Dowling-Degos Disease: Case Report and Review of the Literature
Authors: Batycka-Baran Aleksandra , Baran Wojciech , Hryncewicz-Gwozdz Anita , Burgdorf Walter
Published: March 2010

Dowling-Degos disease (DDD) is an unusual pigmentary disorder usually caused by mutations in keratin 5. A 44-year-old woman in good general health presented due to the recent appearance of numerous pigmented macules on her axillary and anogenital skin. A biopsy showed lacy, finger-like epidermal extensions into the dermis which were heavily pigmented and associated with tiny cysts or dilated follicles. We view DDD as part of a spectrum of disorders which are morphologically related but vary in location and time of expression. In addition, both the clinical and histological differential diagnostic considerations are extensive.
Cerebellum and Source Memory
Authors: Tamagni Corinne , Mondadori Christian R.A. , Valko Philipp O. , Brugger Peter , Schuknecht Bernhard , Linnebank Michael
Published: March 2010

We report the case of a 40-year-old right-handed German-speaking man who presented with ischemic stroke in the territories of the right superior cerebellar artery and posterior inferior cerebellar artery. The objective of the present study was to investigate the consequences of this cerebellar damage with regard to higher cognitive functions. On admission to the stroke unit, the patient presented with dysarthria, right-sided appendicular ataxia, gait ataxia, and right-sided horizontal nystagmus (National Institutes of Health Stroke Scale, NIHSS, score 4). When examined 10 days after his stroke using a set of neuropsychological tests, he showed a marked deficit in the ability to remember when and in which context he had previously encountered verbal material. This aspect of memory, so-called ‘source memory’, is known to be mediated mainly by frontal and medial temporal structures. The present case suggests the existence of a strong functional connectivity between cerebellum and cortical regions underlying specific memory processes.
Tool-Making New Caledonian Crows Have Large Associative Brain Areas
Authors: Mehlhorn Julia , Hunt Gavin R. , Gray Russell D. , Rehkämper Gerd , Güntürkün Onur
Published: March 2010

Animals with a high rate of innovative and associative-based behavior usually have large brains. New Caledonian (NC) crows stand out due to their tool manufacture, their generalized problem-solving abilities and an extremely high degree of encephalization. It is generally assumed that this increased brain size is due to the ability to process, associate and memorize diverse stimuli, thereby enhancing the propensity to invent new and complex behaviors in adaptive ways. However, this premise lacks firm empirical support since encephalization could also result from an increase of only perceptual and/or motor areas. Here, we compared the brain structures of NC crows with those of carrion crows, jays and sparrows. The brains of NC crows were characterized by a relatively large mesopallium, striatopallidal complex, septum and tegmentum. These structures mostly deal with association and motor-learning. This supports the hypothesis that the evolution of innovative or complex behavior requires a brain composition that increases the ability to associate and memorize diverse stimuli in order to execute complex motor output. Since apes show a similar correlation of cerebral growth and cognitive abilities, the evolution of advanced cognitive skills appears to have evolved independently in birds and mammals but with a similar neural orchestration.
Stroke and Action Slowing: Mechanisms, Determinants and Prognosis Value
Authors: Godefroy Olivier , Spagnolo Shirley , Roussel Martine , Boucart Muriel
Published: March 2010

Aim: The present study aimed to determine the mechanisms and determinants of stroke-related action slowing. Methods: Thirty-six stroke patients not presenting any clinical motor deficit of the preferred hand (mean post-stroke delay 11 months) were compared to matched controls on Finger Tapping test (motor speed), Visual Inspection Time test (visual perceptual speed) and Simple and Choice Reaction Time tests. Results: Patients were slower on all tests except Choice Reaction Time: Visual Inspection (p = 0.003), Finger Tapping test (p = 0.001), Simple Reaction Time (p = 0.002) tests were impaired including performance measured with the ipsi-lesional hand. This pattern and the uniform lengthening across the entire reaction time distribution both suggest that psychomotor slowing was due to slowing of perceptual and motor processes. The main determinant of action slowing was lesion location: (1) Visual Inspection Time = right inferior parietal lobulus (OR 18, 95% CI 2.9–108); (2) Finger Tapping = left frontal middle gyrus (OR 18, 95% CI 2.9–108) and lenticular nucleus (OR 59, 95% CI 1.9–1,775), and (3) Simple Reaction Time = right lenticular nucleus (OR 110, 95% CI 8–1,490) and posterior fossa (OR 55, 95% CI 3.4–890). Finally poor outcome depended on Tapping Frequency measured with the contra-lesional index (OR 0.1, 95% CI 0.02–0.5; p = 0.0005) and impairment on the Token test (OR 151, 95% CI 2.24–1136; p = 0.02). Conclusions: This study shows that stroke-related action slowing is mainly due to slowing of perceptual and motor processes. Action slowing was related to lesions of the large network. Finally Tapping Frequency is an independent predictor of outcome. This supports that action slowing is an important consequence of stroke and that it is a promising prognosis index.
Human Umbilical Vessel Diameters and Blood Gas Tensions in the First Two Minutes after Delivery
Authors: McCallum W.D. , McAreavey Dorothea R.M.
Published: March 2010

Human umbilical vein and artery diameters reduce significantly during the first 2 min after delivery, whereas blood gas tensions do not change significantly. Gas tension changes, therefore, cannot account for the reduction in the umbilical vessel diameters which occurs during this time.
Reversible Norepinephrine Binding to Rabbit Myometrium: Relationship to Sites of Known Biological Significance
Authors: Roberts James M. , Keller David W. , Goldfien Alan
Published: March 2010

Catecholamines bind specifically to several cell types and subcellular fractions. This binding is not consistent with binding to the adrenergic receptor. Catecholamines would be expected to bind to sites other than the adrenergic receptor (uptake 1, uptake 2, nerve vesicles, catecholamine-O-methyl transferase and serum albumin). We characterized the binding of 3H-norepinephrine to microsomes prepared from rabbit myometrium. In the presence of antioxidant binding was reversible and 3H-norepinephrine could be recovered bound to microsomes or free in incubation media. The binding was not characteristic of binding to any one known biological site. It may represent binding to a mixture of these sites or may be fortuitous binding to sites of unknown biological significance.
Effects of Gestational Age, Dexamethasone, and Metopirone on Lecithin Concentration in Fetal Lung Tissue and Amniotic Fluid in Rats and Guinea Pigs
Authors: Nelson George H. , Eguchi Katsuto , McPherson James C.
Published: March 2010

There is a significant increase in acetone-precipitable lecithin (APL) concentration with advancing gestation in fetal lung tissue and amniotic fluid in rats. Measurement of the APL concentration in fetal lung tissue and/or amniotic fluid provides an excellent model for evaluation of fetal lung maturation. The surge of lecithin concentration in amniotic fluid lags behind that in fetal lungs by about 1 day. This supports the concept that fetal lungs are a main contributor to the amniotic fluid lecithin pool. Dexamethasone stimulates the biosynthesis of APL in fetal lungs in rats and guinea pigs. These data support the hypothesis that glucocorticoid treatment in the pregnant woman accelerates fetal lung maturation. Metopirone inhibits the biosynthesis of APL in fetal lungs.
In vitro Perfusion Studies of the Human Placenta
Authors: Rice Philip A. , Nesbitt, Jr. Robert E.L. , Rourke James E.
Published: March 2010

In vitro perfusion studies show countertransport of glucose in the human placenta induced by the addition of the nonmetabolizable glucose analog 3–0-methyl-α-D-glucopyranoside (3MG). This ‘uphill’ transport is the movement of a glucose against a concentration gradient caused by the ‘downhill’ movement of the 3MG. This phenomena is a characteristic of a mobile carrier system.
Hormonal Steroids: Effects on the Vascular System
Authors: Solash J. , Perez R. , Keates J.S. , Ramasamy N. , Stein H. , Troyansky D. , Ateyeh, Jr. E. , Jones J.R. , Srinivasan S. , Sawyer P.N.
Published: March 2010

An increase in the incidence of thromboembolic disorders has been associated with oral contraceptive use, though the causative mechanisms remain unclear. Our studies indicate that the contraceptive steroids, irrespective of the intermediary metabolic processes involved, cause changes in the surface charge characteristics of the blood vessel wall and blood cells in the following cases: (i) in experiments using dogs, the hormonal steroids result in a greater reduction in the pore surface charge of veins than in arteries; (ii) in rats, the current induced mesenteric occlusion times are significantly lowered following administration of combined contraceptive steroids; (iii) in humans, the electrophoretic mobilities of erythrocytes and platelets from women taking Ovral and Demulen are lower than in controls, and (iv) there is no significant alteration of plasma coagulation times of women who are on injectable progestin therapy. Demulen and Ovral appear to result in a slight decrease in activated partial thromboplastin times compared to controls.
Permeability of the Vaginal Wall for Viruses in Pregnant Mice
Authors: Georgakopoulos P.A.
Published: March 2010

The permeability of the vaginal mucosa for viruses in pregnant and non pregnant mice has been investigated. As a virus model, a T3-phage suspension labeled with methylene blue was inoculated into the vagina. 18 min after application of the suspension in pregnant mice, phages were detected in circulating blood by in vitro tests. In non pregnant mice, a phagemia was noted 8 min later. The rapid permeability of the vaginal mucosa for viruses during pregnancy has been substantiated by a simultaneous excretion of dye in gastric fluid and in urine. These observations may be due to the hyperemia and increased pelvic blood flow of the genital tract during pregnancy.
Unbound Unconjugated Cortisol in Umbilical Cord and Corresponding Maternal Plasma
Authors: Simmer H.H. , Frankland M.V. , Greipel M.
Published: March 2010

Unbound unconjugated cortisol was measured in cord venous and arterial plasma and in simultaneously obtained maternal venous plasma by equilibrium dialysis at 37 and 5 °C and by centrifugal ultrafiltration at 37 °C. Total cortisol was quantitated by a specific method based on chromatography and competitive protein binding. 67 cases were studied at cesarean section, 7 at vaginal delivery. Regardless of the method used, values of unbound cortisol in cord plasma were found to be much lower than previously reported. The values for unbound cortisol in the mothers exceed approximately 3-fold those in the newborn.
Circulatory Changes in the Reproductive Tissues of Ewes during Pregnancy
Authors: Rosenfeld Charles R. , Morriss, Jr. Frank H. , Makowski Edgar L. , Meschia Giacomo , Battaglia Frederick C.
Published: March 2010

The blood flows to reproductive organs were measured by means of radionuclide-labeled microspheres in 24 pregnant ewes with gestational ages ranging from 38 to 141 days. The microspheres were injected in the left ventricle of the non-anesthetized animal 4–7 days after surgery and while uterine blood flow was recorded continously by means of electromagnetic probes on both uterine arteries. The blood flow to ovaries with corpus luteum was maximum in early pregnancy and greater than in ovaries without corpus luteum. Placental blood flow increased from ∼30 to ∼300 ml/min during the stage of placental growth (40–90 days). In the last 50 days of pregnancy placental weight declined, whereas placental flow continued to rise and attained ∼1,500 ml/min near term. The growth curves of fetal weight and placental blood flow followed a similar pattern, but the early increase in placental flow was more rapid than the increase in fetal weight. Hence placental flow per gram of fetus was larger in early pregnancy (∼9 ml/min·g) than near term (∼0.25 ml/min·g). In twin pregnancies the placenta of each fetus received a smaller blood flow than the placenta of a singleton of comparable age. Mammary blood flow demonstrated no change until the last 60 days, when it increased from ∼10 to ∼200 ml/min. This phenomenon coincided with an increase in mammary weight and the final progressive increase of placental blood flow.
In vitro Perfusion Studies of the Human Placenta Angioradiographic Study of the Maternal Circulation (With Colour Plate I)
Authors: Rourke J.E. , Gould L.V. , Rice P.A. , Nesbitt, Jr. R.E.L.
Published: March 2010

The flow of maternal perfusate through the intervillous space has been monitored by observing the flow of a radiopaque injection. The results of these experiments show that the extracorporeal apparatus devised by us does provide adequate perfusion of the isolated placenta in a manner strikingly similar to that occurring in vivo. Supporting evidence was obtained by dissecting the placenta to locate the distribution of India ink injected with the radiopaque dye.
17β-Hydroxysteroid: NAD (P)-Oxydoreductase Plasma Enzyme-Activity Levels in Threatened Abortion, Inevitable Abortion and Pregnancies complicated by Diabetes mellitus
Authors: Dadze S. , Rose W. , Stock G.
Published: March 2010

Changes in the enzyme-activity levels of the placental steroid enzyme, 17Β-hydroxysteroid:NAD(P)-oxydoreductase were examined in the plasma of women with normal and pathological pregnancies. The behaviour of the enzyme-activity levels in normal pregnancies did not differ from pregnancies complicated by temporary signs of threatened abortion. Imminent and recent inevitable abortions showed significantly higher and old-protracted inevitable abortions significantly lower enzyme levels than normal controls. It is concluded that the placental enzyme in the plasma of pregnant women could be of use in monitoring threatened abortion and distinguishing it from inevitable abortion. In pregnancies complicated by diabetes mellitus, there was increased antenatal incidence of pathological enzyme levels above and below the normal 95 percent tolerance limits in poorly controlled cases, heavy babies, heavy placentas, hydramnion and fetal distress.
The Microscope in Early Embryological Investigation
Authors: Bodemer Charles W.
Published: March 2010

The microscope became an instrument of scientific investigation during the 17th century, its application leading to the discovery of the spermatozoa and profound changes in embryological thought. The severe optical limitations and consequent distrust of the microscope limited its use during the 18th century, but thereafter the instrument gradually improved. By the end of the 19th century, the instrument had achieved a state of excellence and its application had contributed to a knowledge of early generativeprocesses that forms the foundation of modern embryology.
Study into the Mechanisms of Damage of Human Placental Syncytiotrophoblast
Authors: Carr Martin C.
Published: March 2010

Plasma and sera from various sources induced in vitro lysis of human chorionic syncytial trophoblast. In almost all instances the lytic activity was heat labile. Its optimal pH range was between 6.8 and 8.0. Once the trophoblast was exposed to plasma the continued presence of the plasma was not necessary for lysis to occur. The lysis could be inhibited by a variety of substances which could be added hours after the incubation was started and still be effective. The evidence showed that the lytic system required calcium, possessed a thiol group and that a protease was involved. Further, it suggested that two stages were necessary. The first, the initiator of events, was dependent upon a plasma-derived substance, likely complement; the second, the mediator of the lysis, was dependent upon substances inside the syncytial trophoblast, likely lysosomal enzymes.
Increased Urinary Estriol Excretion without Change in Blood Estriol Concentration Resulting from Bed Rest in the Third Trimester of Pregnancy in the Human
Authors: Betz George , Hagerman Dwain D.
Published: March 2010

Placing normally pregnant women at bed rest during the third trimester significantly increased the amount of total estrogen excreted into the urine to 122% of the control value, but the concentration of total serum estriol was not significantly altered. Estriol biosynthesis, secretion, conjugation, metabolism, and excretion are regulated by many poorly understood factors, but for purposes of clinical evaluation of the well-being of the infant, bed rest would appear to be another circumstance under which more reliable information can be obtained by blood instead of urine analysis.
Studies on the Anti-Oestrogenic and Oestrogen-Like Action of Clomiphene Citrate in Women
Authors: Czygan P.-J. , Schulz K.D.
Published: March 2010

The experiments dealed with the regulatory action of clomiphene citrate on the FSH and LH serum levels in women of different endocrine state. The radioimmunologically obtained data can be summarized as follows: (1) In adult women with an eugonadotropic ovarian insufficiencyclomiphene stimulates the FSH- and LH-secretion during treatment, which is followed by a plasma profile comparable to that of normal cycles. This effect probably is due to the antioestrogenic property of the substance. In postmenopausal women with the typical high gonadotropin and low oestrogen levels, clomiphene displays – independent of the treatment schedule and the dose given – only an oestrogenic action, recognizable by the suppression of the FSH- and LH-plasma values. The finding of a plasma gondotropin increase after clomiphene administration in some postmenopausal women with unusual oestrogen excretion indicates that the regulatory effect of the substance mainly depends on the endogenous oestrogen level. Finally a model is given for the possible mode of action of clomiphene in stimulated ovulatory cycles.
Biological Effects of Antibodies to Gonadotropins With colour plate I
Authors: Eshkol Aliza , Lunenfeld B.
Published: March 2010

Some of the contradictory postulates regarding gonadotropin action in infancy were reexamined. For the deprivation of newborn animals of endogenous gonadotropins, antiserum neutralizing theese hormones was administered from birth on. Using this approach it was elucidated that, even during the first week of life, gonadotropins stimulate development of ovarian somatic elements and are indispensable for this process. In the absence of the stimulatory action of endogenous gonadotropins, the normal ovarian development taking place during the first and second week of life was markedly altered and retarded. This was mainly evident from the reduction in the number of follicles which developed, the change in the appearance and ultrastructure of granulosa cells, the deficiency of thecal and of vascular development. That the observed alterations were due specifically to gonadotropin deprivation was proven by the fact that these alterations were prevented by the administration of human gonadotropins to mice deprived of endogenous gonadotropins. Substitution with human gonadotropins permitted the elucidation of the respective role of follicle-stimulating hormone (FSH) and FSH plus luteinizing hormone (LH) in the development of the infantile ovary. This was achieved by the use of HMG and of a biologically ‘pure FSH’ which was obtained by the neutralization of the LH activity present in HMG. FSH was found to be primarily responsible for the stimulation of granulosa cell proliferation, organization and structure. FSH plus LH, in addition to the FSH effects, initiated secretory activity of granulosa cells, increase in intrafollicular spaces, antrum formation, enrichment and maintenance of the theca layer and development of the vascular system. At the age of 14 days, the administration of HMG to gonadotropin-deprived animals even enhanced some of the developmental phases beyond that observed in ovaries of control animals at the same age. Oocyte growth seems to be independent of gonadotropins since it was similar in all experimental groups. The functional integrity of the growing oocytes in gonadotropin-deprived animals could not be assessed in this study.
Use of Androgen Antagonists and Antiandrogens in Studies on Sex Differentiation
Authors: Jost A.
Published: March 2010

his review paper, including some unpublished results, summarizes some of the effects on sex differentiation in male fetuses of drugs which inhibit enzymes involved in steroid hormone synesis or of antiandrogens, especially cyproterone acetate. The former have only very slight effects on morphological sex differentiation. Cyproterone acetate is a very potent antimasculine agent in several species (rabbit, dog and probably others); in other species (rat, guinea pig, calf) the results obtained so far are at variance. Several apparently contradictory data pertaining to the stabilization and differentiation of the Wolffian ducts of the rat fetus are discussed.