Cat's Paw Research Articles

The aphid Ceratovacuna nekoashi (Hemiptera: Aphididae: Hormaphidinae) and its allied species in Korea, Japan and Taiwan

AbstractThe aphid Ceratovacuna nekoashi and its allied species have been a taxonomically difficult group. They form peculiar “cat's‐paw” galls (called “Nekoashi” in Japanese) on Styrax trees and also use Microstegium grasses as their secondary hosts. Through sampling aphids from both Styrax galls and Microstegium grasses in South Korea, Japan and Taiwan, and sequencing their DNA, we made it clear that four distinct species occur in these regions: C. nekoashi (Sasaki), C. oplismeni (Takahashi), C. orientalis (Takahashi) and C. subtropicana sp. nov. In Korea, C. nekoashi forms galls on both S. japonicus and S. obassia, whereas in Japan the species forms galls on the former but not on the latter; our molecular analyses unequivocally indicated the occurrence of a single species in South Korea and mainland Japan. Aphids of the four species on the secondary host were morphologically discriminated from one another. The identity of the primary‐ and secondary‐host generations was also clarified for each species. All four species were found to produce second‐instar sterile soldiers in their Styrax galls, and first‐instar soldiers were found in colonies of C. subtropicana on the secondary host.

Location of cat brain stem neurons that drive sweating

The brain stem premotor pathways controlling most noncardiovascular sympathetic outflows are unknown. Here, we mapped the brain stem neurons that drive sweating, by microinjecting excitant amino acid (L-glutamate or D,L-homocysteate: 0.4-3 nmol) into 420 sites over the pons and medulla of eight chloralose-anesthetized cats (70 mg/kg iv). Sweating was recorded by the electrodermal potential at the ipsilateral forepaw pad. Responses were classified as immediate (<5 s latency) or delayed (>10 s latency). Immediate responses were obtained from 16 sites (1-3 per animal) and were accompanied by no change in blood pressure. Those sites were clustered between the facial nucleus and the pyramidal tract in the rostral ventromedial medulla (RVMM). Microinjections into 33 surrounding sites caused delayed electrodermal responses of lesser amplitude, while the remaining 371 sites evoked none. To retrogradely label bulbospinal neurons that may mediate electrodermal responses, fluorescent latex microspheres were injected into the region of the intermediolateral cell column in the fourth thoracic segment in an earlier preparatory procedure on six of the animals. A cluster of retrogradely labeled neurons was identified between the facial nucleus and the pyramidal tract. Neurons in this discrete region of the RVMM, thus, drive sweating in the cat's paw and may do so via direct spinal projections.

Comparative Anatomy of the Vasculature of the Dog (Canis familiaris) and Domestic Cat (Felis catus) Paw Pad

The microvasculature of footpads in the dog and domestic cat was investigated using histology and scanning electron microscopy of corrosion casts. Methylmethacrylate resin vascular casts for scanning electron microscopy, Indian ink injected whole mount and histological specimens were each prepared, in a series of 16 limbs of 4 adult dogs and 12 limbs of 3 adult domestic cats. The network of blood vessels in the dog paw pad appears to have an intricate pattern, especially with regard to venous outflow forming a peri-arterial venous network. Numerous arteriovenous anastomoses (AVAs) were found in the canine dermis. While, that of the domestic cat had less complex vascular pattern in the footpad without the peri-arterial venous network. AVAs were observed sporadically in the feline dermis. The peri-arterial venous network in the paw pad formed a countercurrent heat exchanger in dogs. When the foot pad is exposed to a cold environment in dogs, the countercurrent heat exchanger serves to prevent heat loss by re-circulating heat back to the body core, adopting an inhospitable environment. AVAs also play a role in regulating the body temperature. A lack of the peri-arterial venous network and few AVAs appear to make felines more prone to suffer from a cold condition than canines.

A Vector–Host System to Fingerprint Virus Tropism

Reporter genes are important tools for assessing vector pharmacology in vivo. Although useful, current systems are limited by (1) the need to generate a new vector for each different reporter, (2) the inability to package reporter genes in small vectors, and (3) variations in reporter gene feedback due to variations in cell-to-cell vector copy number. To circumvent these problems, we have used Cre recombinase as a "cat's paw" to activate reporter genes embedded in transgenic mice. The small Cre gene was introduced into self-complementary adeno-associated viral (scAAV) vectors with limited packaging capacity. Injection of scAAV-Cre vectors into mice with loxP-inactivated luciferase enabled in vivo imaging distributions comparable to the signal observed after AAV-luciferase injection. When injected into mT/mG mice, AAV-Cre converted ubiquitous expression of red fluorescent protein (RFP) to green fluorescent protein (GFP) expression only where the vectors transduced cells. Injection into F(1) hybrid luciferase and mT/mG mice enabled simultaneous three-reporter tracking. This system was able to discriminate cell-specific transduction in all organs tested, with particular usefulness for detecting AAV serotype-specific transduction in the liver, kidney, and muscle. Given that F(1) mice bear exactly one copy of luciferase and one copy of RFP-GFP, each reporter gene is either "on" or "off" in a cell. The Cre system therefore provides a unique quantum method to quantify vector delivery that can be applied when vector capacity is limited.

Education Under Fire: Introduction

Education at the beginning of the twenty-first century is in crisis and contestation. The economic instability of capitalism—reflected in the slowdown in the economic growth trend since the mid-1970s, worsening financial crises, and the growth of draconian neoliberal policies—has had the effect of further compromising a capitalist educational system already beset with problems.… The conflict over the agenda of the powerful with respect to schools is increasingly apparent. On the one side we find: privatization; drastically lowered expectations for students and families; the demonization of teachers; zero-tolerance as a cat's paw for surveillance and control; sort-and-punish curricula; a culture of obedience and conformity; and narrowing definition of learning as job-training and education, i.e., as a product to be bought and sold in the market. On the other side we find: a growing fight-back based on the principle that all human beings are of incalculable value and that life in a just and free society must be geared toward and powered by a profoundly radical idea: that the fullest development of all human beings—regardless of race or ethnicity, origin or background, gender identity, ability or disability—is the necessary condition for the full development of each person; and, conversely, the fullest development of each is the condition for the full development of all.This article can also be found at the Monthly Review website, where most recent articles are published in full.Click here to purchase a PDF version of this article at the Monthly Review website.

Antagonism of prostaglandin F 2 induced bronchoconstriction and blood pressure changes by polyphloretin phosphate in the guinea-pig and cat.

Abstract Polyphloretin phosphate (PPP) when infused intravenously into guinea-pigs or cats antagonized the bronchoconstriction and blood pressure changes elicited by prostaglandin F2α and cat paw slow reacting substance (SRS). The dose required to induce a 50% reduction was 40–80 mg/kg PPP. The effects of histamine were not significantly antagonized by the doses used. PPP itself also had a blood pressure lowering effect. The results suggest that it may act as a prostaglandin and SRS antagonist in vivo.

Cat's Paw

Cat's Paw

Three-dimensional analyses of touch domes in the hairy skin of the cat paw reveal morphological substrates for complex sensory processing

The three-dimensional morphology of the innervation of touch domes in the hairy skin folds of cat forepaws was investigated by the confocal laser scanning microscopic analyses of sections stained immunocytochemically with primary antibodies for protein gene product 9.5, neurofilament 200 and cytokeratin 20 in combination with transmission electron microscopic observations. One square centimeter of interdigital skin can contain as many as 68 touch domes. Each touch dome can have up to 150 Merkel cells and all are innervated by a single large-caliber afferent myelinated nerve fiber at the level of the palisade endings around the guard hair. It gives rise to multiple long, myelinated branches. Each final myelinated branch gives rise to several short and fine unmyelinated branches, supplying approximately 15 Merkel cell–axon complexes. Each Merkel cell is typically contacted by multiple small discoid endings instead of by a large single one. Discoid endings on separate Merkel cells were usually the distal ends of the unmyelinated branches, although, some were en-passant swellings of the branches. Only a few Merkel cell–axon complexes at the marginal zone of each territory could also be supplied by adjacent final myelinated branches. Each Merkel cell is surrounded by protrusions of keratinocytes that are penetrated by several collagen bundles of the dermis. This intricate pattern of innervation may explain the unique irregular discharges of action potentials typical for this type of mechanoreceptor.

Innervation pattern of touch domes in cat paws – three dimensional analysis

The skin is the largest sensory organ in mammals, containing huge numbers of free nerve endings serving as polymodal nociceptors as well as specific corpuscular mechanoreceptors i.e.Meissner, Ruffini and Vater-Pacini corpuscles. Merkel cells with associated nerve terminals functioning as slowly adapting mechanoreceptors are found in hairy skin forming touch domes (“Tastscheiben”) and around whisker hair follikels as well as in glabrous skin particularly in finger tips. The aim of the present investigation was to study the three dimensional arrangement of the innervation of touch domes from the trunk of one afferent nerve fiber to all Merkel endings using confocal laser microscopic analysis (BioRad Radiance 2000 on Nikon E600). Frozen serial sections (150–200 μm thick) from skin folds of the cat paw were stained immunohistochemically using primary antibodies for PGP9.5, S100 and CK20. They were mounted between two cover slips allowing observation from both sides. Sequential sections were reconstructed using the software VGStudioMax. In contrast to previous studies, this method allows quantitative analysis of all observed structures rather than estimating numbers. The largest touch domes consisted of up to 150 Merkel cells. Almost all of them were contacted by a basket of nerve fibers. Each touch dome was innervated by originally only one thick myelinated nerve fiber, branching repeatedly in the subdermis and dermis before the final branches reached 5 to 10 Merkel cells in the epidermis just above the basement membrane.

Cyprus: a modern history

In the troubled island of Cyprus, the national interests and rivalries of Greece and Turkey still collide, the population remains divided between the Greek and Turkish communities and the country is still a cat's paw of outside powers - especially the USA and the now resurgent Russia - as it has been since the acquisition of the island by Britain in 1878. These are problems that have been brought into sharp focus by Cyprus' entry into the European Union. William Mallinson's book is a fast-moving and incisive narrative history which portrays Cyprus as a continuing source of international tension in the Mediterranean and beyond. It features the latest source material from the recently released National Archive, vivid interviews with key players, even reports which raise awkward and embarrassing questions. His critical eye uncovers the underlying story of American and British involvement in the island's affairs, first as a key territory in Cold War politics with its close proximity to the Middle East and Asia and now as a key asset in the 'war on terror'.

Motor unit recruitment during vertebrate locomotion

AbstractVertebrate skeletal muscles act across joints and produce segmental accelerations and therefore animal movement when they contract. Different muscles and different motor units vary in their mechanical contractile properties. Early studies on motor unit recruitment demonstrated orderly recruitment of motor units from the slowest to the fastest during a graded contraction. However, many subsequent studies illustrate conditions when alternative recruitment strategies may exist. Motor unit recruitment during locomotion is thus multifactorial and more complex than typically thought.Different types of motor unit vary in their mechanical properties, including rates of force activation and deactivation, maximum unloaded shortening velocities and the shortening velocities at which maximum mechanical power output and maximum mechanical efficiency occur. In short, it would make mechanical sense to perform fast activities with the faster motor units and slow activities with the slower motor units. However, determining patterns of motor unit recruitment during locomotion has presented experimental challenges.Comparisons between distinct muscles have shown that fast fish swimming and the cat paw shake are activities which employ predominantly the fast and not the slower muscle. Glycogen depletion studies have showed that jumping in the bushbaby uses fast without slow motor units within the vastus lateralis and gastrocnemius muscles. Studies in man show that differential recruitment of the different types of muscle fibre occurs at different times within each running stride. It is suggested that vertebrates may have a strategy of recruiting the motor units that are most mechanically suited for the different locomotor demands. However, we have much to learn about motor recruitment patterns during locomotion.

The 'Cat's Paw': Canada and the United Nations Temporary Commission on Korea

Canada played an important role in the United Nations Temporary Commission on Korea that was established in 1947. The long-forgotten commission supervised elections in the southern half of the divided peninsula in 1948 and found them 'fair and free.' This legitimized the emerging state of South Korea and provided the basis for United Nations intervention in the Korean War of 1950. This essay probes the formation of the commission, the role that Canada played within it, and the commission's impact on Korea at the time. In contrast to more conventional interpretations of the Canadian role in the commission, this article suggests that the Canadian role displayed fierce fluctuations but eventually became closely linked to the US position. In its quest to prove itself a faithful ally of the United States, the Liberal government subordinated the interests of reunification of the Korean peninsula to confrontation with the Soviet Union, helped polarize the politics of the peninsula, and facilitated the creation of a brutal regime in the South in a flawed election. The author suggests the problems associated with Canadian foreign policy toward Korea at the time are rooted in Eurocentrism and in misguided notions of US 'isolationism' among makers of foreign policy of that era. Le Canada a jou� un r�le important dans la Commission temporaire des Nations Unies sur la Cor�e, qui fut cr��e en 1947. Tomb�e dans l'oubli depuis longtemps, cette commission supervisa les �lections dans la moiti� sud de la p�ninsule divis�e en deux en 1948 et les d�clara � justes et libres �. Cette proclamation ent�rina la cr�ation du nouvel �tat de la Cor�e du Sud et fournit une justification pour l'intervention des Nations Unies dans la guerre de Cor�e de 1950. Cet essai se penche sur la formation de la commission, le r�le que joua le Canada au sein de celle-ci et l'impact qu'elle eut sur la Cor�e � l'�poque. Contrairement � des interpr�tations plus conventionnelles du r�le jou� par le Canada dans la commission, l'essai sugg�re qu'il connut nombre de fluctuations, mais finit par �tre �troitement align� sur la position am�ricaine. Dans ses efforts visant � prouver la fiabilit� de son alliance avec les �tats-Unis, le gouvernement lib�ral fit passer au second plan les int�r�ts de la r�unification de la p�ninsule cor�enne pour privil�gier l'affrontement avec l'Union sovi�tique, il contribua � polariser la politique dans la p�ninsule et favorisa la cr�ation d'un r�gime brutal dans le Sud � la suite d'une �lection douteuse. L'auteur sugg�re que les probl�mes associ�s � la politique �trang�re canadienne envers la Cor�e �taient, � l'�poque, ancr�s dans l'eurocentrisme et les fausses notions au sujet de l'isolationnisme am�ricain qui pr�valaient parmi les responsables de la politique �trang�re de l'�poque.

The ‘Cat's Paw’: Canada and the United Nations Temporary Commission on Korea

The ‘Cat's Paw’: Canada and the United Nations Temporary Commission on Korea

Hemidesmosome protein dynamics in live epithelial cells.

Hemidesmosomes mediate stable anchorage of epithelial cells to laminin-5 in the basement membrane zone and have been likened to spot-welds. Indeed, it has been assumed that hemidesmosomes are not dynamic, at least when compared to other matrix adhesion sites including focal contacts. We tested this notion by monitoring the fate of green fluorescent protein (GFP)-tagged human integrin beta4 subunit (GFP-hbeta4) and GFP-tagged 180-kD human bullous pemphigoid (BP) autoantigen (GFP-BP180) in live cultures of 804G cells that assemble numerous mature hemidesmosomes. In subconfluent 804G cells, both GFP-hbeta4 and GFP-BP180 protein clusters are not stable but assemble into and disassemble out of cat paw-like arrays at a relatively rapid rate. In confluent populations of 804G cells, although some cat paw-like clusters of both GFP-hbeta4 and GFP-BP180 are stable over periods of >60 min, other GFP-hbeta4 and GFP-BP180 protein arrays form and/or disappear during the same time period. Moreover, individual labeled particles show considerable motility in the plane of the membrane. Fluorescence recovery after photobleaching analyses provide a further indication of the dynamics of hemidesmosome proteins. In particular, bleached GFP-hbeta4 protein clusters in confluent cells recover signal within about 30 min, indicating that there is a relatively rapid turnover of hemidesmosome components in protein arrays clustered along the substratum attached surface of a cell. The rate of recovery is dependent on an intact microfilament system. In sharp contrast, bleached GFP-BP180 protein clusters in confluent cells fail to recover signal even when observed for longer than 60 min. To evaluate hemidesmosome protein dynamics in motile cells, we monitored GFP-hbeta4 and GFP-BP180 in 804G cells populating scrape wound sites in vitro. In these migratory cells, which lack mature hemidesmosomes, integrin beta4 subunit and BP180 protein clusters progressively assemble and disassemble into linear and cat-paw arrays. In summary, hemidesmosome protein clusters, like their counterparts in focal contacts, are dynamic. We discuss these results in relation to hemidesmosome functions.

Konstruktionsprinzipien an der Vorder- und Hinterpfote der Hauskatze (Felis catus). 2. Mitteilung: Gelenke

According to form and range of mobility the joints of the cat's paw (articulationes manus et pedis) are adjusted to two basic functions: as far as they are used for walking in the different gaits they show components in the sagittal plane that particularly correspond to the digitigrade dog. With regard to cat-specific behaviour, i.e. climbing and catching, specific characteristics of the joints for movements in the R-plane (rotation) and A-plane (abduction/adduction) can be distinguished. For this reason highly specialized types of articulations occur in cat's paw that are unique compared to other mammals and that mostly have not been described yet. In this context, like in the skeleton (see first communication), function-adapted divergences can also be found between the joints of the forepaw and hindpaw of the cat.

The spatial relationship between the perineuronal proteoglycan network and the synaptic boutons as visualized by double staining with cationic colloidal iron method and anti-calbindin-D-28K immunohistochemistry in rat cerebellar nuclei.

The present study demonstrated the precise spatial relationship between meshes in the perineuronal proteoglycan network and the terminal boutons of synaptically associated axons. Sections from the rat cerebellum were stained with cationic colloidal iron (pH 1.0-1.5), and successively immunostained with anti-calbindin-D-28K monoclonal antibody. Cationic iron stained sulfated proteoglycans around the nerve cell of the medial cerebellar nucleus, whereas the anti-calbindin antibody labeled the Purkinje cells including their axons terminating on large neurons in the cerebellar nucleus. It was found that each synaptic bouton fits into a mesh of the perineuronal network. The individual meshes appeared to be divided by partitions faintly stained with the colloidal iron. Electron microscopy of cationic colloidal iron-stained ultrathin sections revealed that the synaptic boutons were separated from each other by the proteoglycan matrix and that each of them was further divided into two or more contact areas of presynaptic membrane by the same matrix. This suggests that individual synapses are protected against the effects of adjacent synaptic transmission, and that each of them may be subdivided by this manner of partitioning, like pads of a cat's paw.

The birdseye figured grain in sugar maple (Acer saccharum): literature review, nomenclature, and structural characteristics

Little is known about the "birdseye" figured grain of sugar maple (Acer saccharum Marsh.). This paper clarifies and expands the discussion of birdseye sugar maple by describing the similarities and differences with figured grains in other species, as well as discussing important features of its peculiar anatomy. Sections are also provided that discuss the proposed causes of the birdseye grain, detail birdseye sugar maple's geographic distribution, and address what is known about genetics and birdseye maple. Possible variations on the birdseye theme (e.g., roundeye, fingernail, cat's paw, distorted) are documented, and a new set of descriptive terminology is established. Finally, further observations and speculations on the birdseye phenomena are provided, and research directions are suggested.

Peripheral GABA A receptors: evidence for peripheral primary afferent depolarization

We propose that the primary afferent depolarization that follows GABA A receptor activation in the spinal cord also occurs in the periphery. As evidence, the present study localizes β2/β3 and α1 subunits of the GABA A receptor on 10–14% of the unmyelinated primary afferents axons in the glabrous skin of the cat paw. Behavioral studies demonstrate that local peripheral injection of the GABA A agonist muscimol at a low concentration (2.0 μM) attenuates, and at a high concentration (1 mM) enhances, formalin-induced nociceptive behaviors. Intraplantar injection of muscimol alone at a high dose evokes thermal hyperalgesia. Bicuculline, a GABA A antagonist, prevents these muscimol-induced changes in behavior. The muscimol-induced effects are due to local rather than systemic or central activation of GABA A receptors, as such effects are not observed in the contralateral paw. We interpret these findings to indicate that activation of GABA A receptors by low concentrations of muscimol depolarizes peripheral primary afferent terminals, a phenomenon we call peripheral primary afferent depolarization, in turn reducing the size of the peripheral action potentials and concomitantly reducing the amount of algogenic substances released from the peripheral terminals of these fibers. This sequence of events presumably results in a reduction in nociceptor activation. Higher concentrations of muscimol further depolarize GABA A receptor-containing terminals, which then initiates action potentials in nociceptors analogous to the appearance of dorsal root reflexes that arise following activation of GABA A receptors on central primary afferent terminals. These latter events reverse the analgesic effects of GABA A ligands and lead to potentiation of nociceptive input. Thus, the present study provides anatomical and behavioral evidence supporting a bimodal role for GABA A receptors in the modulation of peripheral nociceptive transmission.

Shaping of the cat paw for food taking and object manipulation: an X-ray analysis.

The kinematics of the cat distal forelimb during food-taking were analysed to obtain information on the movement processes within the paw before and during object taking in a species without monosynaptic corticomotoneuronal projections. The behaviour was investigated with two tests: either the table test (TT, food offered on a table located at ground level in a reaching distance of 22 and 28 cm) or the horizontal test (HT, food offered in a small container located at shoulder level, height 18-25 cm, reaching distance 6-12 cm). In five animals, the changes in configuration and the conjoint actions of the wrist, the metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints were assessed with three-dimensional X-ray cinematography (time resolution 20 ms, spatial resolution 1 mm) and video analysis. While approaching the target, the digits were first extended and subsequently abducted. This 'preshaping' consisted of combined angular changes in the MCP and PIP joints, thereby attaining an adequate grip aperture. Each cat used a stable strategy, but different cats used different strategies. In the TT, preshaping involved an MCP extension and a PIP flexion. In the HT, predominant extension of the MCP, predominant extension of the PIP, or a combination of both were used, followed by MCP flexion and PIP flexion. The grip aperture started to decrease before object contact, earlier in the TT, later in the HT. Grasping was achieved by flexion of first the PIP and later the MCP. The X-ray analysis gave evidence for individuated digit movements. Correlation analysis of the angular position of the joints between the different phalanges showed that digits 3 and 4 acted in concert, as did digits 2 and 5, but with clear independence between the different pairs. Furthermore, the different phalanges served different purposes during the grasp. Digits 3, 4 established object contact, digits 2, 5 were mainly used to stabilize the paw onto the surface. The cat distal forelimb displays a refined movement repertoire during the preshaping and grasping phase of food-taking. During the preshaping phase, the kinematics resembled in some aspects the situation in humans. The results demonstrate the ability of the polysynaptic projections from the cortico-motoneuronal system to organize differentiated distal limb movements, including individuated movements of the digits.

Testing the toxicity of sediments contaminated with diesel fuel using glochidia and juvenile mussels (Bivalvia, Unionidae)

Sediment toxicity was evaluated for one site upstream and three sites downstream of a diesel fuel spill that occurred in Fish Creek (OH and IN) in September 1993 using glochidia and juvenile unionid mussels. This fourth order tributary of the St. Joseph River has the only known remaining population of white cat's paw pearly mussel, Epioblasma obliquata perobliqua, and populations of several other federal and state endangered mussels. The impact of the oil spill was of great concern because of the potential long term threat it poses to the survival of these mussels. Sediment samples collected two years after the spill contained low heavy metal concentrations, and detectable, but not quantifiable levels of organic components of diesel fuel. These levels coincided with their lack of toxicity to juvenile Villosa villosa and Lampsilis siliquoidea mussels after 9-day exposures. Fish Creek sediments may be toxic to L. siliquoidea glochidia.