bluuebunny/crossref_metadata_2025 huggingface dataset:
BEHAVIOR OF TACHYON IN STRING COSMOLOGY BASED ON GAUGED WZW MODEL
Authors: LEE SUNGGEUN , NAM SOONKEON
Published: February 2009

We investigate a string theoretic cosmological model in the context of the gauged Wess–Zumino–Witten model. Our model is based on a product of non-compact coset space and a spectator flat space; [ SL (2, R)/ U (1)]k × ℝ2. We extend the formerly studied semiclassical consideration with infinite Kac–Moody level k to a finite one. In this case, the tachyon field appears in the effective action, and we solve the Einstein equation to determine the behavior of tachyon as a function of time. We find that tachyon field dominates over dilaton field in early times. In particular, we consider the energy conditions of the matter fields consisting of the dilaton and the tachyon which affect the initial singularity. We find that not only the strong energy but also the null energy condition is violated.
QUARK LAGRANGIAN DIAGONALIZATION VERSUS NON-DIAGONAL KINETIC TERMS
Authors: DURET Q. , MACHET B. , VYSOTSKY M. I.
Published: February 2009

Loop corrections induce a dependence on the momentum squared of the coefficients of the Standard Model Lagrangian, making highly nontrivial (or even impossible) the diagonalization of its quadratic part. Fortunately, the introduction of appropriate counterterms solves this puzzle.
SIGNATURE SPLITTING IN 173W WITH TRIAXIAL PARTICLE ROTOR MODEL
Authors: QI B. , ZHANG S. Q. , WANG S. Y. , MENG J.
Published: February 2009

A particle rotor model with a quasi-neutron coupled with a triaxially deformed rotor is applied to study signature splitting for bands with intruder orbital ν7/2+[633] and nonintruder orbital ν5/2-[512] in 173 W . Excellent agreement with the observed energy spectra has been achieved for both bands. Signature splitting for band ν7/2+[633], and band ν5/2-[512] before the onset of signature inversion, is satisfactorily reproduced by introducing the γ degree of freedom. The phase and amplitude of signature splitting in band ν5/2-[512] are attributed to strong competition between 2f7/2 and 1h9/2 components. However, the self-consistent explanation of signature inversion in band ν5/2-[512] is beyond the present one quasi-neutron coupled with a triaxially deformed rotor.
LEAST ENERGY NODAL SOLUTIONS OF THE BREZIS–NIRENBERG PROBLEM IN DIMENSION N = 5
Authors: ROSELLI PAOLO , WILLEM MICHEL
Published: February 2009

We prove the existence of (a pair of) least energy sign changing solutions of [Formula: see text] when Ω is a bounded domain in ℝN, N = 5 and λ is slightly smaller than λ1, the first eigenvalue of -Δ with homogeneous Dirichlet boundary conditions on Ω.
A FUNCTION APPROXIMATION METHOD FOR IMAGES WITH GRADING REGIONS
Authors: MIYAMOTO KENTARO , KAMINA TETSUO , SUGIYAMA TETSUO , KAMEYAMA KEISUKE , TORAICHI KAZUO , OHMIYA YASUHIRO
Published: February 2009

In the last decade, many function-approximation methods for illustration images have been proposed. However, these methods cannot process more complex full color images effectively, even when some simple regularity of color transitions such as gradations appear in images. In this paper, we propose a rigorous function-approximation method that is applicable for gradation images. This method performs image segmentation that recognizes a gradation pattern as one region. This segmentation is performed by recursively approximating the tones of colors using multiple regression analysis of 2-variable functions. We compare the proposed method and the conventional methods with regard to the quality of enlarged images and the efficiency of image description and reproduction. The experimental results show that our approach is higher in quality, smaller in data size, and faster in computational costs than the conventional methods.
OPTIMAL RATE ALLOCATION FOR LOGO WATERMARKING
Authors: LAO YUANWEI , ZHENG YUAN F.
Published: February 2009

Compression of logo as an image is addressed in logo watermarking, in which a framework of joint Human Vision System (HVS) model and rate allocation theory in the wavelet domain is applied. Under this framework, a novel logo watermarking algorithm using reversible discrete wavelet transform is proposed. Based on multi-level wavelet decomposition of both host and logo images, a well-known HVS model is applied to locate the visually insensitive area in the host for embedding, while the rate allocation theory determines how the logo is compressed and embedded by using the statistical characteristics of the logo. For a given overall embedding distortion, quantization step-sizes of different logo subbands are analytically determined to maximize the fidelity of the extracted logo under the imperceptibility constraint. The adaptive system is thus applicable to different hosts and logos without tuning the parameters manually. It is proved to be robust against various types of attacks and is quite suitable for hardware implementations. Since logo is considered as an image in this new algorithm, the watermarking approach developed can be extended in general to image-in-image embedding.
NEW VISUALIZATION MODES FOR EFFECTIVE IMAGE PRESENTATION
Authors: PORTA MARCO
Published: February 2009

In this paper we consider the problem of effective browsing of collections of images. In particular, we address those situations where it is necessary to find a limited number of images satisfying certain criteria, as well as the very common case in which the user, not having a clear idea about what to search, needs to explore the entire picture database to identify what he or she simply likes. The approaches we propose try to find good trade-offs between browsing time and quality of the exploration. The article has a twofold purpose: on the one hand, it presents a selection of the new image display methods we have developed in the last years, which differentiate from those considered to date by the Information Visualization community; on the other hand, it illustrates the results obtained through comparative tests performed on a subset of the developed display modes, with the main aim to prove the feasibility of their use as substitutes for the usual "grid" arrangement.
AN EFFICIENT APPROACH TO COLOR IMAGE SEGMENTATION USING INTERMEDIATE FEATURES OF MAXIMUM OVERLAP WAVELET TRANSFORM IN PEAK FINDING ALGORITHM
Authors: VASUKI S. , GANESAN L.
Published: February 2009

In this paper a novel color image segmentation algorithm based on homogeneity histogram is proposed. The proposed approach uses intermediate features of maximum overlap wavelet transform (IMOWT). The IMOWT, which is the efficient transform, has been applied to color image segmentation for its time effectiveness, flexibility and translation invariance which are required for good segmentation results. The set of transform coefficients derived from wavelet domain are subjected to an efficient peak finding algorithm (PFA). PFA is employed to identify the most significant peaks of the homogeneity histogram. While we process the homogeneity histogram, both local and global information are taken into account. This is particularly helpful in taking care of small objects and local variations of the image. This method provides better segmentation results when compared to the direct application of PFA and Mean shift algorithm.
CERAMIC-BASED NANOCOMPOSITES FOR FUNCTIONAL APPLICATIONS
Authors: FÉNYI BALÁZS , KOSZOR ORSOLYA , BALÁZSI CSABA
Published: February 2009

Silicon-nitride-based composites with 3 wt% of multi-wall and single-wall carbon nanotubes and graphene have been prepared. A manufacturing process has been worked out to avoid the damage of nanotubes and graphene during sintering. This method provides their preservation even in severe circumstances at temperature 1700°C and gas pressure 2 MPa. In this work, the conductivity according to the type and concentration of the carbon additives was observed by applying four-point DC resistance measurements. Insulator and conductor composites can be produced depending on the type of additives.
PROTON-CONDUCTING POLYMERS AS ELECTROLYTE FOR FUEL CELLS
Authors: EBRASU DANIELA , STAMATIN IOAN , VASEASHTA ASHOK
Published: February 2009

The objective of this investigation is to evaluate a series of polymer electrolyte membrane materials based on sulfonated ladder pyridine polymers and SiO 2 nanoparticles that enhance water retention and favor high temperature (> 120°C) applications. Nanoparticles are used to improve water uptake at levels of 20–38% to increase the level of sulfonation. A study of relevant characteristics of these polymers will provide an alternative to existing polymers, thus offering simple processing steps, as well as nonexotic polymers and higher performances.
Voluntary movement and repetitive transcranial magnetic stimulation over human motor cortex
Authors: Todd Gabrielle , Rogasch Nigel C. , Flavel Stanley C. , Ridding Michael C.
Published: February 2009

Repetitive transcranial magnetic stimulation (rTMS) can induce short-term reorganization of human motor cortex. Here, we investigated the effect of rTMS during relaxation and weak voluntary muscle contraction on motor cortex excitability and hand function. Subjects ( n = 60) participated in one of four studies. Single transcranial magnetic stimuli were delivered over the motor area of the first dorsal interosseus for measurement of motor evoked potential (MEP) size before and after real or sham rTMS delivered at an intensity of 80% of active motor threshold. rTMS involved trains of stimuli applied at 6 Hz for 5 s and repeated every 30 s for 10 min. Resting MEP size was suppressed for 15 min after rTMS during relaxation. However, MEP suppression was abolished when additional brief voluntary contractions were performed before and after rTMS ( study 1). Resting MEP size was suppressed for 30 min after rTMS during weak voluntary contraction. MEP suppression was present even though voluntary contractions were performed before and after rTMS ( study 2). The MEP suppression most likely reflects a decrease in motor cortical excitability. Surprisingly, rTMS during voluntary contraction did not alter maximal finger tapping speed or performance on a grooved pegboard test, object grip and lift task ( study 3), and visuomotor tracking task ( study 4). These studies document the complex relationship between voluntary movement and rTMS-induced plasticity in motor cortex. This work has implications for the optimization of rTMS parameters for improved efficacy and potential therapeutic applications.
Contribution of the carotid body chemoreceptors to eupneic ventilation in the intact, unanesthetized dog
Authors: Blain Grégory M. , Smith Curtis A. , Henderson Kathleen S. , Dempsey Jerome A.
Published: February 2009

We used extracorporeal perfusion of the reversibly isolated carotid sinus region to determine the effects of specific carotid body (CB) chemoreceptor inhibition on eupneic ventilation (V̇i) in the resting, awake, intact dog. Four female spayed dogs were studied during wakefulness when CB was perfused with 1) normoxic, normocapnic blood; and 2) hyperoxic (>500 mmHg), hypocapnic (∼20 mmHg) blood to maximally inhibit the CB tonic activity. We found that CB perfusion per se (normoxic-normocapnic) had no effect on V̇i. CB inhibition caused marked reductions in V̇i (−60%, range 49–80%) and inspiratory flow rate (−58%, range 44–87%) 24–41 s following the onset of CB perfusion. Thereafter, a partial compensatory response was observed, and a steady state in V̇i was reached after 50–76 s following the onset of CB perfusion. This steady-state tidal volume-mediated hypoventilation (∼31%) coincided with a significant reduction in mean diaphragm electromyogram (−24%) and increase in mean arterial pressure (+12 mmHg), which persisted for 7–25 min until CB perfusion was stopped, despite a substantial increase in CO2 retention (+9 Torr, arterial Pco2) and systemic respiratory acidosis. We interpret these data to mean that CB chemoreceptors contribute more than one-half to the total eupneic drive to breathe in the normoxic, intact, awake animal. We speculate that this CB contribution consists of both the normal tonic sensory input from the CB chemoreceptors to medullary respiratory controllers, as well as a strong modulatory effect on central chemoreceptor responsiveness to CO2.
Maintenance Treatment for GERD: Residual Symptoms Are Associated with Psychological Distress
Authors: van der Velden A.W. , de Wit N.J. , Quartero A.O. , Grobbee D.E. , Numans M.E.
Published: February 2009

Aim: The aim of this study was to explore determinants of residual reflux symptoms among patients with gastroesophageal reflux disease (GERD) despite maintenance treatment with acid suppressive medication (ASM). Methods: Primary care GERD patients on chronic ASM were classified as symptom-free (55%) or symptomatic (45%) according to the impact of their residual reflux symptoms (QolRad). They were compared with respect to lifestyle (BMI, alcohol, smoking, physical exercise), compliance (daily ASM dosage), disease history, psychological factors (SCL-90) and quality of life (SF-36). Results: None of the investigated lifestyle factors, nor dosage and disease history were related to residual symptoms. However, symptomatic patients differed from patients with relief on all psychological and quality of life dimensions. In a multiple logistic regression model somatization, hostility, mental health, body pain, as well as gender were independently associated with residual symptoms; the derived ROC curve had an AUC of 0.78. Conclusions: The majority of GERD patients is symptom-free on chronic ASM; they display a healthy psychological state and high quality of life. Residual symptoms however, are associated with psychological distress and lower quality of life. Recognition of this subgroup might hold the key to improving long-term management of gastroesophageal reflux.
Magnetic Resonance Imaging in Frontotemporal Dementia Shows Subcortical Atrophy
Authors: Chow Tiffany W. , Izenberg Aaron , Binns Malcolm A. , Freedman Morris , Stuss Donald T. , Scott Chris J.M. , Ramirez Joel , Black Sandra E.
Published: February 2009

Background/Aims: The clinical syndrome of the frontotemporal dementias (FTD) overlaps with frontal-subcortical circuit syndromes. We explored the extent to which subcortical atrophy on structural magnetic resonance imaging may indicate a subcortical contribution to the progression of FTD. Methods: This cross-sectional case-control study compared striatal and thalamic gray matter volumes and functional levels from 30 FTD cases and 30 age- and gender-matched controls. Results: The FTD group had significantly more atrophy in all gray matter subcortical regions, correlating with ipsilateral frontocortical atrophy. Subcortical atrophy was also associated with functional disability. Subcortical asymmetry was most marked in subjects with primary progressive aphasia. Conclusion: Subcortical gray matter atrophy may contribute as significantly to symptoms of FTD as cortical atrophy.
Relation of Trp64Arg Polymorphism of Beta 3-Adrenergic Receptor Gene to Adipocytokines and Fat Distribution in Obese Patients
Authors: de Luis D.A. , Aller R. , Izaola O. , Gonzalez Sagrado M. , Conde R.
Published: February 2009

Background/Aim: Obesity has multiple causes and is determined by the interaction between genetic and environmental factors. A genetic factor is a (Trp64Arg) missense mutation in the beta 3-adrenergic receptor. The aim of our study was to investigate the influence of Trp64Arg polymorphism in the beta 3-adrenergic receptor gene on weight, adipocytokines, insulin resistance, and fat distribution in obese patients. Methods: A population of 217 nondiabetic obese Caucasian outpatients was analyzed. Indirect calorimetry and tetrapolar bioimpedance results, blood pressure, nutritional intake with 3-day food records, and biochemical parameters were evaluated. The genotype of beta 3-adrenergic receptor gene polymorphism (Trp64Arg) was studied. Results: The mean age of the patients was 44.3 ± 16.4 years, and the mean body mass index was 35.2 ± 5.2. One hundred and eighty-six patients (52 males and 134 females; 85.8%) had the genotype Trp64/Trp64 (wild-type group), and 31 patients (11 males and 20 females; 14.2%) had the genotype Trp64/Arg64 (mutant group). In the mutant group, body mass index, weight, fat mass, waist-to-hip ratio, waist circumference, and C-reactive protein levels were higher than in the wild-type group. The adipocytokine levels were similar in both groups. Conclusion: The patients of the mutant group (Trp64/Arg64) had higher body mass index, weight, waist circumference, fat mass, waist-to-hip ratio, and C-reactive protein values than those of the wild-type group.
Seasonal histological changes in the ovaries of a mountain stream teleost, Schizothorax richardsonii (Gray and Hard)
Authors: Bisht Jitendra S. , Joshi Manju Lata
Published: February 2009

In S. richardsonii, unlike its testis, the whole of the ovary is fertile. The oogonia pass through seven maturation stages to form the ripe ova. The residual oogonia are responsible for the development of the new crop of oogonia. The zonation of the ooplasm reveals that a majority of the oocytes have a darkly stained inner and a lightly stained outer zone. The yolk nucleus probably has some relationship with the process of vitellogenesis. The nucleoJi are produced by the division and fragmentation of the nucleolus. Extrusion of nucleoli appears to be associated with the formation of yolk. The formation of yolk globules in the oocyte begins in the periphery of the ooplasm and moves inward till the whole of the ooplasm is impregnated with yolk. As the yolk vesicles are PAS-positive in this fish, they contain mucopolysaccharides. The ovarian cycle can be divided into five stages. The ovary becomes much enlarged and distended in the month of October and delicate and thin in March. The spawning season extends from late October to December and the ovary exhibits asynchronism.
Significance of the pattern of motor innervation of the intrinsic laryngeal muscles of cat
Authors: Abo El-Enene M.A.
Published: February 2009

Simple and compound forms of motor endings, showing a particular distribution, were found in the intrinsic laryngeal muscles of the cat. The muscles carrying compound and multiple endings were stained densely black with Sudan black B; while the muscles with simple and single endings showed black and pale fibres. A probable relationship is suggested between the contraction properties and the pattern of motor innervation of intrinsic laryngeal muscles of the cat.
Identification of sex from tarsal bones
Authors: Singh Shamer , Singh S.P.
Published: February 2009

Bone weight as a discriminative factor for identification of sex was studied in tarsal bones (172 calcanei and 164 tali) from the Varanasi region. The DPs for the weight of these bones identified sex correctly in a good percentage of cases, especially from the male bones. The findings suggest weight of tarsal bones as a useful metrical feature for discriminating sexual dimorphism.
Histochemical investigations on the symphysis menti in the human fetus related to fetal skeletal maturation in the hand and foot
Authors: Kjær Inger
Published: February 2009

Histochemical investigations on the symphysis menti region were performed on 72 human embryos and fetuses of crown-rump lengths (CRL) ranging from 16 to 162 mm, presenting skeletal maturity indices (CNO = composite number of ossified bones in the hand and foot) ranging from 0–0 to 19–11. The symphysis menti region is described in five developmental stages according to morphology and histochemical reactions at the interzone, enchondral bone formation, and MeckeΓs cartilage. The stages are described according to histochemical reactions for glycosaminoglucuronoglycans, collagen, glycogen, alkaline and acid phosphatase, and non-specific AS esterase. Silver impregnation followed by X-ray and histochemical control for Ca++ deposits supplemented the study. Special attention was paid to a fusion of the bilateral MeckeΓs cartilages in the midline characteristic of stage II. This is a finding not previously recorded in human fetuses. It is suggested to designate this fusion ‘the rostral connection’. Histochemically, the fusion appeared as ordinary cartilage matrix (chondroitin -4- and/or -6- sulphate). The absence of a rostral connection characteristic of stage III is discussed. On the basis of reactions for glycosaminoglycans and activity of hydrolytic enzymes, the symphysis is characterized as a growth zone, active in mandibular growth in width as well as in length, during the first half of the prenatal period. The material available did not justify a description of skeletal development in the symphysis menti as a function of CRL, of skeletal maturation in the hand and foot, or as a function of a combination of these parameters.
Ultrastructural development of bone marrow adipose cell
Authors: Tavassoli Mehdi
Published: February 2009

The postnatal development of bone marrow adipose cells was studied by sequential examination of marrow tissue obtained from the tibia and femur of 1- to 8-week-old rabbits. The bone marrow adipocyte begins to develop 2 weeks after birth. Its cellular origin differs from the ‘fibroblast-like’ cell that is the progenitor of the extra-medullary adipocyte. The marrow pre-adipocyte is associated with the sinus endothelium and adventitial cells, but is not associated with collagen and does not contain abundant organized rough endoplasmic reticulum. Unlike the extramedullary adipocyte, the course of differentiation of the medullary adipocyte is not characterized by the appearance of glycogen; furthermore, during the coalescence of lipid droplets to form larger fat globules, cytoplasmic organelles, such as mitochondria and ribosomes, are trapped within the lipid substance to form intralipid vacuoles containing degraded cytoplasmic organelles. The possible significance of these morphologic differences between the developing bone marrow adipocyte and that of its extramedullary counterpart is discussed.
Histological and histochemical aspects of the mucosa of the nasal conchae in the zebu (Bos indicus)
Authors: Nogueira J.C. , Alves J.B. , Godinho H.P.
Published: February 2009

In various respiratory areas of the mucosa of the nasal conchae of the zebu (Bos indicus) there is a quantitative variation of goblet cells. The glands are tubular or tubulo-alveolar, having morphologically serous and mucous cells. The excretory ducts are formed by non-secreting cells. The goblet cells and glands elaborate a glycoprotein. The carbohydrate portion is probably an association of neutral mucopolysaccharides, sulphated acid mucopolysaccharides and sialic acid and its proteic portion contains α-amino radicals. Tryptophan- and tyrosine-rich proteins are demonstrated only in the glandular secretion.
Constitution and body proportions in different strains of rats
Authors: Riesenfeld Alphonse
Published: February 2009

(1) There are considerable differences in body constitution in different strains of rats, ranging from very robust to very gracile forms. The differences are greater in the larger males than in the smaller females. (2) Craniofacial and postcranial proportions of the trunk in domesticated strains of rats differ either uniformly or mosaically from the wild form.(3) Nasal shape differs greatly in rats ranging from extreme leptorrhine to extreme platyrrhine forms, giving a total range greater than in human populations.(4) Fisher 344 rats have long tails and extremities and Buffalo and GRL short tails and extremities.(5) Wistar and ACI rats have longer tails than wild rats but do not differ significantly from wild rats in the relative length of their other extremities.(6) The relationship between tail and extremity length is under genetic control which is concordant in Fisher, Buffalo and GRL rats, but discordant in the Lewis, Wistar and ACI strains.(7) There is no connection between relative extremity length and total body constitution since short-limbed strains occupy both the highest (Buffalo) and lowest (GRL) levels of robusticity, and strains that do not differ in relative extremity length from wild rats differ greatly from each other in constitutional type (Wistar and ACI).(8) Differences of relative extremity length and nasal shape in rats have their parallels in human populations. But in human populations they follow Allen’s ecological ‘rule’ and can be duplicated experimentally. In rats here used, however, they do not result from any known ecological pressures, but from the genetic factors acting in breeding isolates.
Vergleichende Untersuchungen am Trachealepithel verschiedener Säuger
Authors: Pavelka M. , Ronge H.R. , Stockinger G.
Published: February 2009

Tracheal epithelia of ten different mammals were investigated with the light and the electron microscope. Characteristic differences were found concerning the thickness of the epithelia, the length of the cilia, the density of the cells in the epithelia, the numerical distribution of the different cells and their ultrastructure. Special attention was paid to the morphology of the kinetosomes. Brush cells and chromaffin cells, which are sparsely distributed in the different tracheal epithelia, were discussed.
Funktionelle Morphologie der Theca interna im Bläschenfollikel des menschlichen Ovars
Authors: Schaar Herbert
Published: February 2009

A study of histological serial sections of human ovaries and histochemical reactions established that several cell types differentiate in the theca interna during the formation and development of tertiary follicles (2nd growth period). This leads, in turn, to triple-layering of the theca interna in follicles of the 2nd resting period. The inner thecal layer consists of fusiform cells from the basement membrane, which are apposed to the membrana granulosa and show a strong positive reaction to alkaline phosphatases. A tropic function for the follicular epithelium must be assigned to this layer. The middle layer consists of epitheloid thecal cells, which show a strong positive reaction to 3β-ol-steroid hydrogenase. These represent the estrogen glands of the follicle. The outer layer of the theca interna, whose transition to the theca externa is indistinct, also has fusiform cells, which are available as reserve material for the differentiation of further epitheloid thecal cells to pre-ovulatory follicles in later periods of development.
Stature estimation from femur and humerus by regression and autometry
Authors: Kate B.R. , Mujumdar R.D.
Published: February 2009

Estimation of stature from a single extremity bone is a common forensic practice and many regression equations are given by various workers. In India, Pearson’s formula is the most commonly used method to determine the height. These regression equations were subjected to verification on 194 (97 pairs) femora and 102 (51 pairs) humeri from India. It was seen that the Pearsonian formulae did not give exact results. The regression formulae differed statistically in both sexes in femur and humerus. These are calculated and given. This finding once again proves the necessity of having norms or formulae for the specific groups, when reliable results are required. In addition, the proportion between humerus length and femur length is also verified. This has evolutionary significance. In addition to the usual method as above, a method of the proportion these bones individually bear to the stature of the same person to which the bones belong is worked out both as a multiplication factor and percentage proportion to the body stature. It has been amply demonstrated and concluded that this method be called ‘autometry’ and further that this seems to be more reliable method than the tedious yet variable and unreliable results the various formulae give. This autometry seems to have a consistency, being constant in both sexes and all races, thus evolving a ‘human race autometry’.
Internal surface and fine structure of the rat seminal vesicle
Authors: Hücker H. , Aumüller G.
Published: February 2009

The seminal vesicle of the rat was studied with scanning and transmission electron microscopy. The internal surface of the organ is partitioned into small areas by a system of elevated ridges of connective tissue and covered by a columnar epithelium. This consists of small basal cells, presumably reserve elements, and larger ones containing the typical cell organelles involved in protein synthesis. The surface of the cell is covered with slender microvilli, varying in height and number from region to region. It is suggested that they are involved in the maintenance of hydration and/or regulation of low molecular weight substances in the secretion product. The latter develops from small granules which pass the apical cell border and then fuse together as larger drops.
Further observations on the ear in fossorial mammals with special considerations of Chlamyphorus truncatus (Harlan)
Authors: Segall Walter
Published: February 2009

The morphology of the external and the middle ear (auditory ossicles) in Chlamyphorus truncatus is influenced by its fossorial life. The external auditory canal consists of three parts. The most distal part is a short (cartilaginous) auricle which reaches anteriorly close behind the eye. Posteriorly to the auricle is a long, thin bony duct which consists of two segments, movable against each other. This tube leads through a narrow porus into the third part of the canal, the recessus meatus, which is enclosed in the bulla. The recessus with the narrow porus is characteristic for many fossorials and has a morphology with physical characteristics of a resonator (Helmholtz). The malleus and the stapes in Ch. truncatus are also influenced by fossorial life. Based on the dorsal view of the malleus head, the Xenarthra can be divided into two groups. To the first division belong the Dasypodidae with the Chlamyphorinae and Dasypodinae, to the second the Myrmecophagidae and Bradypodidae. The malleus of Cyclopes, a myrme-cophagid, differs from that in the other Myrmecophaginae and is similar to the malleus in the Dasypodinae. Two kinds of experiments should be undertaken: (a) physiologic-acoustic experiments in a fossorial to determine the effect of the recessus and (b) acoustic experiments varying the dimensions and positions of a tube and a porus leading into a resonator.
Some ultrastructural observations on human palmar stratum corneum
Authors: Spearman R.I.C. , Hardy J.A.
Published: February 2009

Ultrastructure of human palmar stratum corneum was examined for cell junctions and cytoplasmic material. Interdigitated microvilli with laterally placed desmosomes occur as in the guinea pig plantar epidermis, but the microvilli are shorter and less uniform in man. Most of these processes are either conical or truncated in shape, as distinct from the relatively smooth cell surfaces except for sigma-shaped junctions in hairy sites. It is suggested that this provides strength against shearing force in the palm and sole. There is less cytoplasmic breakdown in palmar horny cells than in hairy sites.
Ultrastrukturelle Lokalisation der Mg++- und Ca++-aktivierbaren Adenosintriphosphatase im Spinalganglion von Schaf und Ziege
Authors: Hummel G. , Weyrauch D.
Published: February 2009

Light and electron microscopic investigations on the Mg++- and Ca++-activated ATPase of sheep and goat dorsal root ganglion have been carried out. Reaction products occur on plasma membranes and interfaces between neurons and sheath cells, between adjacent sheath cells and on the surface of unmyelinated fibers. Cytoplasmic protrusions of ganglion cells and numerous surface increasing invaginations of sheath membranes form close connections between neurons and sheath cells.
The points of nerve entry and the intramuscular nerve branchings in the human muscles of mastication
Authors: Rakhawy M.T. , Shehata S.H. , Badawy Z.H.
Published: February 2009

The sites of nerve entry and the intramuscular nerve branchings in the masseter, temporalis, medial and lateral pterygoid muscles were studied. A total of 55 muscles were taken from eight infants and only one adult subject. It was found that for each of the four muscles of mastication, the nerves entered at a nearly fixed point. The masseter and medial pterygoid have their point of nerve entry very near to their origin, the temporalis very near to its insertion, the lateral pterygoid midway between its origin and its insertion. The intramuscular nerve branchings were investigated in the four muscles and, according to their relation to the direction of the muscle fibres, three patterns have been recognized. The results obtained were compared with those of other workers on other muscles.
Embryonic and postnatal growth of rat and mouse
Authors: Goedbloed J.F.
Published: February 2009

(1) Data on the embryonic growth of several organs and of many different types of tissue in the mouse and rat are presented. (2) The concept developmental age is introduced, because it leads to an age estimate that is better correlated with the developmental stage. (3) The general growth pattern of the organs and tissues studied agrees with that found for the whole animal, consisting of phases with exponential growth separated by breaks. In the majority of the organs the breaks occur at the same time as in the whole animal. (4) The decrease in the growth rate at the end of phase EII is definitely smaller in the majority of the organs than in the whole animal. (5) Breaks occurring at other times than those found in the whole animal seem to take place in a few organs, and in the mouse at the embryonic age of about 17 days in a large number of organs.
Degeneration in the adult rat spinal cord following systemic treatment with 6-hydroxydopamine
Authors: Wong W.C.
Published: February 2009

3 and 5 days following intravenous injection of 6-OHDA (100 mg/kg) in adult rats, the Nauta technique demonstrated sparse axon degeneration in laminae V, VII, IX and X of Rexed in the mid-thoracic spinal cord and also in the lateral and ventral white columns. This showed that in adult rats 6-OHDA may pass the blood-brain barrier at the level of the spinal cord. An unexpected finding was the absence of degeneration in the laminae dorsal to lamina V, where noradrenergic nerve terminals are known to occur.
Pregnancy and progeny in rats treated with prostaglandin A1
Authors: Jackson C.W. , Persaud T.V.N.
Published: February 2009

The effects of the long-acting prostaglandin Ax upon pregnancy and fetal development were investigated in Long-Evans rats. The animals were treated by the intra-uterine route either on gestational day 14 with 25 μg PGA1 or with 50 μg on day 17 of gestation. The incidence of fetal resorptions was significantly increased compared to the controls following treatment on gestational day 17. A significantly high incidence of nonspecific malformations was also induced in the offspring as a result of the treatment. There were no significant differences between experimental and control fetal and placental weights. The total protein content of fetal liver following treatment with PGA1 was not significantly reduced. Microscopic examination of placentas showed a consistent decrease in the thickness of the decidua basalis following treatment with 25 μg PGA1 on day 14 of gestation. The ovaries and umbilical cords showed no changes. In addition, treatment of rats daily with 200 μg PGA1, administered subcutaneously, on gestational days 9–12 or 12–15 did not affect the development of the conceptuses.
Mechanism of action of α-chlorhydrin on the testes and caput epididymidis of rat, gerbil (Meriones hurrianae)  bat and mouse
Authors: Dixit V.P. , Lohiya N.K.
Published: February 2009

Chronic administration of α-chlorhydrin caused lesions of rat, gerbil and bat testicles selectively. The seminiferous epithelium became systematically depleted of spermatogenic elements. α-Chlorhydrin did not produce lesion of the caput epididymidis. Sloughing of the epithelial lining did not occur. No obstruction of the lumen of the epididymal duct was seen. The growth of androgen-dependent organs, i.e. seminal vesicles, epididymis and levator ani muscles was suppressed. α-Chlorhydrin caused no response directly on the epididymides. Subcutaneous or oral administration of α-chlorhydrin for a period of 3–5 weeks caused no response in the testes and epididymides of the mouse.
Histoautoradiographie der DNS in Trophoblastriesenzellen der Plazenta der Maus
Authors: Heine H.
Published: February 2009

The trophoblast giant cells of the mouse placenta are mitotically inactive. Nucleolar RNA synthesis is apparently at a standstill. The high nuclear DNA contents of these cells shown by 3H-thymidine marking is conceived by us to be a synthesis of metabolic nuclear DNA. Thus protein synthesis in trophoblast giant cells has been taken over by a metabolic DNA.
Effect of glucagon on the principal islets of a fresh-water fish, Channa punctatus (Bloch)
Authors: Gill T.S. , Khanna S.S.
Published: February 2009

Intramuscular administration of crystalline mammalian glucagon (0.5–2.0 mg/kg body weight) evokes significant cytological alterations in the principal islets of Channa punctatus, a fresh-water fish. Initially there is degeneration of the α-cells but later the /5-cells are also atrophied. Regressive changes in some of the α-cells have been interpreted to reflect their possible role in glucagon secretion. The degeneration of β-cells appears to be secondary to the fluctuations in the blood glucose level, induced by exogenous glucagon.
Isolation of single osteons and osteon lamellae
Authors: Frasca Peter , Harper Richard A. , Katz Lawrence
Published: February 2009

Single human osteons were isolated by propagating fractures along their natural boundaries. Furthermore, decalcified osteons were mechanically manipulated to expose their interlamellar interfaces, making possible the study of collagen fibers by means of scanning electron microscopy (SEM). Isolation of single osteons of a wide range of lengths, as described in this paper, makes possible for the first time the study of their mechanical properties in all possible modes. SEM studies of exposed lamellar interfaces reveal that collagen fiber orientations are more complex than previously suggested and suggest further studies in an effort to solve past controversies on collagen fiber orientations in human bone.
Cholinesterase activity in some human lymphatic organs
Authors: Rakhawy M.T. , Tarkhan A.A. , Zakaria A.M.
Published: February 2009

(1) Cholinesterase activity was investigated in some human lymphatic organs (palatine tonsil, ‘normal’ spleen, ‘bilharziaΓ spleen, thymus, lymph node and appendix) using Gomori’s modification of Koelle and Friedenwald’s thiocholine iodide method, hydrolyzing acetylthiocholine iodide and butyrylthiocholíne iodide, (a) Acetyl-and butyrylcholinesterases seemed to be different enzymes; but when they have the same pattern of activity, the latter generally offers a weaker reaction, (b) All the lymphatic follicles of the tonsil, those found in the cortex of the cervical lymph nodes as well as those present in the appendix, were stainable with both acetyl- and butyrylcholinesterase. (c) Acetylcholinesterase activity was not demonstrated in the Malpighian bodies of the ‘normal’ spleen, but the reaction was strongly present in the blood vessels (including the central arterioles) as well as in the capsule and the different components of the trabecular system, (d) In ‘bilharziaΓ splenomegaly a relatively strong activity started to appear in the Malpighian corpuscles, manifested as a brownish precipitate in their centres. Also some patchy positive areas began to make their appearance in the tissue of the red pulp and had a particular arrangement around the Malpighian corpuscules, in such a way as to ‘wall them off’ from the tissue of the red pulp, (e) In the thymus no acetylcholinesterase activity was encountered, except in Hassal’s corpuscles and in the trabeculae between the thymic lobules. The data obtained in this work were discussed in relation to previous works in other laboratories and it seems that a species difference exists. Cholinesterases may be present in the lymphatic tissue in order to get rid of some potentially toxic esters resulting from the necrobiotic phenomena accompanying the high mitotic activity found especially in the germinal centres of the lymphoid follicles. There are many unanswered questions about the coexistence of the phosphatases and cholinesterases in the same places; their concomitant association in the lymphatic tissue may represent a special case within the framework of a more general mechanism.
L’encéphale de la loche d’étang, Misgurnus fossilis (L.), 1758 (poissons, téléostéens, Cobitidae)
Authors: Ridet J.M. , Bauchot R. , Diagne M.
Published: February 2009

The brain of the Pond-loach (Misgurnus fossilis)is very closely related to that of Cyprinidae. In the Medulla oblongata, the facial lobe – in relation with the skin taste buds, especially on the barbels – is bigger than the vagal lobes – which are related with the mouth taste buds. The intraspecific relations between brainweight and body-weight or various body lengths show a real sexual dimorphism (brain dimegaly). The interspecific brain-bodyweight relationship shows an allometric coefficient of 0.505 in males and 0.485 in females, very close to that of the Rainbow trout. The encephalization index (63) is very close to that of the Tench, and a little lower than that of the Cyprinidae as a whole.
Elektronenmikroskopische Untersuchungen über die Entwicklung des Tubulus seminiferus unmittelbar nach der Geburt bis zum vollendeten ersten Lebensjahr
Authors: Hadziselimovic F.
Published: February 2009

The development of the seminiferous tubule in the first year of life was studied with the electron microscope in five biopsies of normal testes. When HCG stimulation ceases, the fetal Sertoli cell changes into the Sa-Sertoli cell. The possibility of the fetal Sertoli cell having a hormone producing role is discussed. Gonocytes can be detected until the third month post natum. In addition to the gonocytes fetal, transitional, Ap and Ad spermatogonia are also present in the first year of life.
Einfluss der Immobilisation auf die Spermiogenese
Authors: Meitner E.R.
Published: February 2009

The author investigated the influence of immobilization stress on spermiogenesis in rats. After 96 h immobilization, histological changes began to manifest in the form of a practically complete disappearance of the cell population of the wall of seminiferous tubule as well as a markedly increased number of cells with pathologic mitoses. Enzymological investigations have shown in particular groups (24, 48 and 96 h immobilization) various changes of activity (of acid and alkaline phosphatase, nonspecific esterase and glucose-6-phosphatase) which, after temporary negativity, became positive again in the last group.
The structure of the suprarenal venous system and its possible functional significance
Authors: Gonzalo-Sanz L.M. , Insausti R.
Published: February 2009

The structure of the suprarenal venous system of 25 human suprarenal glands has been studied. From a structural point of view, four portions of the suprarenal vein have been distinguished: the proximal section, the hilus section, the section of the prehilus collaterals, and the distal section. In the hilus section and the section of the prehilus collaterals, the structure of the tunica media is more complex. In the hilus section, spiral fibres are found besides the longitudinal muscle fibres. Three strata of fibres can be observed in the section of the prehilus collaterals at the point where these veins drain into the central vein: two longitudinal strata, external and internal, and a third intermediate stratum corresponding to the looped fibres. The spiral and looped fibres, on contracting, can function as a sphincter. The longitudinal fibres, by means of the traction they exert on the stroma and connective capsule of the suprarenal, increase the intraglandular pressure while decreasing the periglandular pressure. A sympathetic stimulus provokes an increase in the secretion of adrenalin, and, at the same time, a contraction of the muscle fibres of the suprarenal venous system. Under these conditions, the venous return makes use of the emissary veins; and in this way, the secreted adrenalin establishes a close contact with the cortico-suprarenal parenchyma.
Vascular patterns in the chick embryo spinal cord in normal and experimentally modified development
Authors: Camosso M.E. , Roncali L. , Ambrosi G.
Published: February 2009

The development of the vascular patterns of the lumbosacral segments of the chick embryo spinal cord has been analyzed in normal as well as in experimental conditions, after complete removal of the hind limb primordium. The results indicate that in both conditions the development of the vascular network follows the time-space sequence of the cytoarchitectural modifications of the cord, supporting the view that the vascularization does not exert a morphogenetic influence.
Calcitonin cells and unusual follicles of the thyroid of the Indian grey mongoose, Herpestes edwardsi (Geoffroy)
Authors: Swarup Krishna , Das Vijai Krishna
Published: February 2009

Histological preparations of thyroid, parathyroid and thymus glands of Herpestes edwardsi were examined for calcitonin cells. They reveal that (1) the thyroid calcitonin cells are oval, rounded and rarely elongated in shape; these cells and their nuclei are distinctly larger than those of the follicular cells and their nuclei; (2) calcitonin cells are unevenly distributed in the thyroid, with the result that certain portions of the thyroid are completely devoid of these cells; (3) on an average, calcitonin cells are in a ratio of 10–15 cells/100 follicular cells; (4) the parathyroid and thymus glands do not display calcitonin cells, and (5) the thyroid gland displays unusual follicles of two categories, (a) follicles with ciliated epithelial cells and (b) follicles with squamous epithelium.
Vegetative innervation of the esophagus
Authors: Pedrosa Juan Ángel , Hernández Carlos José , Rodrigo José , Vidal María Antonia
Published: February 2009

The osmium tetroxide-zinc iodide technique has been applied to the study of the tela submucosa and tunica muscularis in the esophagus of the cat and the rhesus monkey. Other than the classical terminal vegetative formation, three types of endings were found, classified as perifascicular, free and intramuscular. The comparative results between cat and rhesus monkey show differences in the distribution and number of such endings. A sensory functional significance is proposed and discussed.
Développement du pancréas d’un amphibien urodèle, Pleurodeles waltlii (Michah)
Authors: Magnier J.
Published: February 2009

The study of the pancreas development in Pleurodeles waltlii Michah (amphibian urodele) shows the following characteristics: 1) The dorsal rudiment is formed the first, even before the irrigation of the tree producing branchial buds (end of stage 30). This rudiment is formed by isolation of cells rich in vitellus from the dorsal wall of the archenteron. The ventral rudiment, which is massive and more developed on the right side than on the left, appears only a few hours later. The two rudiments fuse at the eclosion time (after stage 35). The elements of the exocrine pancreas, which are the first formed, take place little before the eclosion (stage 33b). They come from the transformation of the cells rich in vitellus, with embryonic character. Solid masses of these cells are first formed and then hollowed in tubules which secondarily join the central pancreatic canal of rudiments. The endocrine elements, which are as rare in the larva as in the adult, appear only after the eclosion. The B cells are formed first (stage 35).