baber/WOPTO huggingface dataset:
Patent FR-2600118-A1 (FR)
Title: Transparent conical special wind machine replacing the roof of a building
Inventor: PLANTEFEVE FERNAND
IPC: F03D3/04
Filed: 1986-06-16
Abstract: The invention relates to a transparent conical wind machine making it possible to recover wind energy by producing electrical energy and also simultaneously or otherwise making it possible to recover solar energy directly through the same wind machine using a collector which is also conical, and to transform it into electricity or heat using a collector of the fluid or similar type. The wind machine comprises a transparent cone 1 forming a cap for a conical solar collector 9. A shaft 3 supports the wind machine 1. A block bearing 7 receives the end of the spindle 3. The bottom end of the wind machine 5 is designed so that when it rotates, a cushion of air supports its weight. A speed multiplier and an alternator 8 operate according to the rotation of the shaft 3. Amongst the most beneficial applications of the invention, mention may be made of energy savings when this method is mounted as a roof on a dwelling or other construction.
Patent FR-2602532-A1 (FR)
IPC: E04B1/10
Filed: 1986-08-07
Abstract: Construction consisting of the combination of the modular system with light primary framework (2) with an outer, thick and resistant masonry (22, 23), of means for assembling these two internal and external structures by stapling with intercalary spaces completing the insulating qualities of the materials. It is intended for the building of a dwelling house, preferably individual, but which may be extended to other types of buildings, in order to obtain a house built with hard material providing for the security and the permanency of the building while increasing the comfort of the user due to the modular elements, while reducing cost.
Patent FR-2602654-A1 (FR)
Title: Structure d'assise, notamment pour siege a dossier reglable
Inventor: FOURREY FRANCOIS
IPC: B60N2/00
Filed: 1986-08-14
Abstract: CETTE STRUCTURE COMPORTE UN ELEMENT HELICOIDAL TUBULAIRE 16 QUI FORME SUCCESSIVEMENT UN CONTOUR D'ASSISE 22 PUIS UN ELEMENT DE LIAISON AU PLANCHER 24, 26. SON EXTREMITE SUPERIEURE 18 EST TRAVERSEE PAR UN AXE 20 D'ARTICULATION SUR L'UN DES COTES D'UN DOSSIER 1 ET EST RELIEE PAR DES GOUSSETS 38, 40 A L'ORGANE DE LIAISON. L'EXTREMITE OPPOSEE 52 EST RELIEE AU CADRE DE CONTOUR D'ASSISE PAR DES GOUSSETS 30, 32. TOUT EFFORT EXERCE PAR LE DOSSIER SUR L'EXTREMITE SUPERIEURE 18 TENDANT A DEROULER L'ELEMENT HELICOIDAL EST AINSI ABSORBE PAR CELUI-CI.
Patent FR-2602955-A1 (FR)
Title: Composition for cleaning and disinfecting milking equipment
Inventor: BARDONESCHI GILBERT
IPC: A01N33/04
Filed: 1986-08-19
Abstract: The present invention relates to a composition for cleaning and disinfecting milking equipment, characterised in that it consists of the combination, in a single phase, of a cleaning product and a disinfecting product whose active molecule is an alkylalkylenediamine whose alkyl radical has between 8 and 18 carbon atoms while the alkylene radical has between 2 and 4 carbon atoms.
Patent FR-2590008-A1 (FR)
Title: Procede et appareil de fermeture de porte de four de traitement de dispositifs microelectroniques
IPC: H01L21/00
Filed: 1986-09-02
Abstract: L'INVENTION CONCERNE UN APPAREIL ET UN PROCEDE DE FERMETURE DE PORTE. ELLE SE RAPPORTE A UN APPAREIL DANS LEQUEL UN TRONCON 24, COMPRENANT UN SOUFFLET, EST MAINTENU DE MANIERE ETANCHE CONTRE UNE PORTE 32 ET CONTRE UN ORGANE DE FIXATION 20 DE MANIERE QU'UNE PELLE 52, PORTANT DES TRANCHES 56 A TRAITER, PUISSE ETRE DEPLACEE, LE MANCHE DE LA PELLE 52 ETANT RETENU A L'INTERIEUR D'UN ORGANE DE SUPPORT 12 QUI A UN FOND FERME 14. APPLICATION A LA FERMETURE DES FOURS DE TRAITEMENT UTILISES POUR LA FABRICATION DES DISPOSITIFS MICROELECTRONIQUES.
Patent FR-2604252-A1 (FR)
Inventor: TAILLEBOIS JACQUES
IPC: G01B11/02
Filed: 1986-09-22
Abstract: The sensor consists of three optical fibres (1, 2, 3). The ends of the fibres forming the probe are located in the same plane (4). There is one transmitting fibre (1) and two receiving fibres (2, 3) of different kinds respectively. The fibres are not necessarily parallel to each other and have different numerical apertures. The sensor enables the distance between the end of the probe and a target object to be measured.
Patent FR-2592751-A1 (FR)
Title: Circuit de commande pour la transmission de signaux
Inventor: ZUK BORYS
IPC: H04L25/04
Filed: 1987-01-09
Abstract: Le circuit de commande pour la transmission de signaux de l'invention comprend un dispositif 12, 14, 16, 18, 19, 20, 22, 24, 26 pour rétablir et détecter l'amplitude et la fréquence d'un signal E2 reçu d'une section 81 d'un câble téléphonique et pour propager jusqu'à la section suivante du câble téléphonique les signaux rétablis uniquement si le signal reçu a une amplitude supérieure à un niveau prédéterminé et une fréquence comprise dans une gamme prédéterminée. (CF DESSIN DANS BOPI)
Patent WO-8804092-A1 (WO)
Inventor: DUBUT PATRICK
IPC: A61B8/00
Filed: 1987-11-24
Abstract: La liaison électrique entre les circuits (13, 14) de commande d'une sonde et les faces métallisées (5, 6) des éléments (2) piézo-électriques de cette sonde est assurée par des métallisations (7, 8) réalisées sur des pièces, support (1) ou lame (4) au contact de ces faces métallisées. La liaison mécanique et électrique entre ces métallisations peut être assurée par une mince couche de colle (19, 20) non conductrice.
Patent FR-2609651-A1 (FR)
Title: Process for the treatment of organic residues containing mercury
Inventor: DELWAULLE JEAN-JACQUES
IPC: B09B3/00
Filed: 1987-01-16
Abstract: The invention relates to a process for treating organic residues containing mercury at least partially combined in the sulphide form. This process comprises at least a first stage according to which the mercury is dissolved by chlorine in oxidising acidic medium and insoluble organic compounds are separated from the solution, which compounds can then be destroyed by incineration, and a second stage according to which the mercury is complexed by aqueous ammonia at a pH adjusted to precipitate the complexed mercury whereas the copper possibly present forms a soluble complex, and the precipitate formed is collected separately.
Patent FR-2610951-A1 (FR)
Inventor: CAHUZAC GEORGES JEAN JOSEPH
IPC: D03D13/00
Filed: 1987-02-17
Abstract: This reinforcement is formed by a basic pattern constituted by fifteen woof threads R in a staggered arrangement forming six vertical columns 1 to 6 of alternately two and three threads and at least five horizontal lines 1 to 5 each of three threads, and by six imbricated layers C1 to C6 of at least two parallel threads, namely at least twelve threads a, b, c . . . 1, each connecting every third woof thread of the same column in two adjacent lines and the warp threads of the consecutive layers connecting the woof threads in alternating columns.
Patent FR-2611708-A1 (FR)
Title: Procede de production d'acides alcane-sulfoniques
Inventor: BAPTISTE HUBERT
IPC: B01J10/00
Filed: 1987-02-25
Abstract: PROCEDE DE FABRICATION D'UN ACIDE ALCANE SULFONIQUE PAR L'HYDROLYSE A CHAUD D'UN CHLORURE D'ALCANE SULFONYLE, DE PREFERENCE CONTINU; LA REACTION D'HYDROLYSE EST DECLENCHEE PAR L'APPLICATION INSTANTANEE DE L'ENERGIE LIBEREE PAR LE CHANGEMENT D'ETAT DE L'UN DES REACTIFS INTERNES AU SYSTEME.
Patent FR-2595268-A1 (FR)
Title: Montage tournant pour fixer en position un bol centrifuge pendant la rotation d'une centrifugeuse
Inventor: DARNELL LAWRENCE WAYNE
IPC: B04B1/02
Filed: 1987-03-09
Abstract: UN MONTAGE DE BOL CENTRIFUGE COMPORTE UNE BASE 12 ET UN OU PLUSIEURS LEVIERS ARTICULES 20 DISPOSES SUR CETTE BASE: CES LEVIERS PEUVENT ETRE DEPLACES DEPUIS UNE PREMIERE POSITION DE NON-CONTACT DANS UNE DEUXIEME POSITION DE CONTACT, DANS LAQUELLE, SOIT ILS SONT EN CONTACT POUR TENIR LE BOL, SOIT ILS DEPLACENT D'AUTRES ELEMENTS TELS QUE DES ELEMENTS D'ETANCHEITE 16 DISPOSES SUR LA BASE, SOIT ILS DEPLACENT DES POUSSOIRS 18 QUI A LEUR TOUR DEPLACENT LES ELEMENTS D'ETANCHEITE EN CONTACT AVEC LE BOL.
Patent FR-2598653-A1 (FR)
Title: Process for manufacturing air chambers for tyres
Inventor: OHNISHI MOTOJI
IPC: B29C65/74
Filed: 1987-05-14
Abstract: The invention relates to the manufacture of air chambers. It relates to a manufacturing process in which the ends of a tube 6 of a thermoplastic material are cut off by cutters 2a, 2b of a cutting member 1 which simultaneously ensure the heating of the cut face, between 250 and 350 DEG C, for 2 to 4 s. Next, the cutting member 1 and its base 5 are withdrawn and the cut faces are immediately brought into abutment by moving the holding members 3, 4 closer together. Application to the manufacture of air chambers for bicycle tyres.
Patent FR-2621043-A1 (FR)
Title: Polymeres fluores echangeurs d'ions contenant des agregats metalliques dans la masse ou en surface et procede pour les obtenir
Inventor: PLATZER OLIVIER
IPC: C25B9/23
Filed: 1987-09-25
Abstract: L'invention concerne une composition comprenant des agrégats métalliques et au moins un polymère fluoré échangeur d'ions, et plus particulièrement sous la forme de membranes chargées d'agrégats dans la masse et pouvant être revêtues de plusieurs couches de polymère contenant des agrégats. Ces produits sont obtenus par irradiation de membranes ou de polymère fluoré en solution contenant les ions métalliques à réduire.
Patent FR-2604951-A1 (FR)
Title: Feuilles de copie travaillant par pression, et formulaires et ensembles a enveloppe les comportant
Inventor: PARKER JOHN EDWARD
IPC: B41M5/10
Filed: 1987-10-14
Abstract: L'INVENTION CONCERNE LES FEUILLES DE COPIE TRAVAILLANT PAR PRESSION. ELLE SE RAPPORTE A UN ENSEMBLE COMPRENANT UNE PREMIERE FEUILLE 1 DE COPIE, AYANT UN REVETEMENT SENSIBLE, ET UNE SECONDE FEUILLE 3 AYANT UN REVETEMENT REVELATEUR, UNE PRESSION PROVOQUANT LA REACTION DU REVETEMENT SENSIBLE ET DU REVETEMENT REVELATEUR DES DEUX FEUILLES ET DONNANT UN MARQUAGE RELATIVEMENT PALE. SELON L'INVENTION, UNE MATIERE SECHE 2 D'IMPRESSION, ANALOGUE A CELLE DU PAPIER CARBONE, EST APPLIQUEE SUR UNE PARTIE AU MOINS DU REVETEMENT SENSIBLE, ET ELLE ACCENTUE LE CONTRASTE ET LA LARGEUR DES TRAITS DES ECRITURES FORMEES. APPLICATION A LA REALISATION DE FORMULAIRES ENFERMES DANS DES ENVELOPPES.
Patent FR-2621617-A1 (FR)
Title: Cylindre de presse pour la fabrication de papier ou pate a papier
Inventor: DUPOYET GUY
IPC: D21F3/08
Filed: 1987-10-09
Abstract: Ce cylindre de presse est du type comportant des trous ménagés à la surface périphérique de celui-ci et destinés à aspirer l'eau ou similaire contenue dans la pâte à papier. Le diamètre de ces trous 12 est supérieur à leur profondeur. De préférence, les trous 12 ont, en section transversale, un profil étudié de façon à exercer un effet de ventouse.
Patent FR-2622646-A1 (FR)
Title: Girder for supporting and stiffening boards, and shuttering panel incorporating such girders
Inventor: BEZIAT BERNARD
IPC: E04G11/50
Filed: 1987-10-28
Abstract: Girder for supporting and stiffening boards, particularly to constitute shuttering panels, each girder 1 having to be secured to the panel 2 by nailing, screwing or the like and consisting of a metal section 3 having a support face 4 for the board; the support face 4 is discontinuous and has one or more longitudinal openings 5, the section 3 has an internal longitudinal channel section 7 to the rear of the opening 5 and opening outwards through this opening, and inside this channel section 7 is engaged and retained a continuous insert 8 extending over the length of the girder, the longitudinal part of the insert which appears facing the opening 5 forming, in cross-section, a V which is open in the direction of the opening 5 and whose wings 9 bear against the wall of the channel section, this longitudinal part of the insert being arranged to receive and retain the fixing means.
Patent WO-8808731-A1 (WO)
Inventor: REYRAUD JEAN-LOUIS
IPC: A63B21/055
Filed: 1988-05-11
Abstract: L'objet de l'invention est un appareil de gymnastique et rééducation polyfonctionnel, caractérisé en ce qu'il est constitué d'un cadre-guide (1) rectangulaire horizontal à l'intérieur duquel sont susceptibles de se déplacer, parallèlement à l'axe longitudinal dudit cadre-guide, deux plateaux horizontaux (5, 6), mobiles à va-et-vient de part et d'autre d'une position intermédiaire dite de repos en étant rappelés constamment élastiquement vers ladite position de repos et de moyens (21) d'accrochage ou appui d'une ou plusieurs parties du corps, solidaires dudit cadre-guide (1) et déplaçables suivant plusieurs positions prédéterminées en vue de multiplier les possibilités de positionnement du corps vis-à-vis, d'une part, des deux plateaux et, d'autre part, desdits moyens d'accrochage ou appui. Application notamment à la gymnastique et à la rééducation.
Patent WO-8809611-A1 (WO)
Inventor: CASSAGNE SERGE
IPC: A01G7/00
Filed: 1988-06-03
Abstract: L'extrémité coupée (22) d'un rameau (18) de plante aquatique est engagée dans l'embouchure (21) d'un tube de dégagement gazeux (19) qui part d'une cuve de photosynthèse (2) contenant le rameau (18). Le tube (19) établit une liaison de vase communicant (2) entre la cuve de photosynthèse (2) et une cuve (4) dans laquelle un tube à essais (26) recueille le dégagement. Entre les deux cuves, le tube passe par un compartiment (3) d'observation du dégagement. L'appareil a un fond transparent (16) permettant de le poser sur la table lumineuse d'un rétroprojecteur pour projeter l'image de l'expérience sur un écran. Utilisation pédagogique.
Patent FR-2628837-A1 (FR)
Title: Liquid or paste filled sachet bursting measuring appts. - uses two plates with one fixed and one adjustable, with fixed plate connected to pressure measuring device
Inventor: PLANCHARD CHRISTIAN
IPC: G01N3/10
Filed: 1988-03-18
Abstract: The appts. has two parallel plates (5,6) which define an interface designed to receive the sachet (18) whose bursting pressure is to be measured. The sachet is placed between the two places (5,6) which can be displaced w.r.t. each other. The first plate (5) is the pressure transmission plate which is acted on by a motorised screw (11). The pressure exerted by the plate (5) is transferred to the other plate (6) via the sachet. The second plate resists the applied force and presses against a pressure compression force applied to the sachet. ADVANTAGE - Enables person sending sachet as parcel whether it can withstand rigours of postage.
Patent FR-2628707-A1 (FR)
IPC: B31B19/86
Filed: 1988-03-21
Abstract: The machine for attaching handles to carrier bags has a rotatable feeder (2) with four fixed plates (8) and four movable plates (11). Bags are placed on a fixed plate (8) from a stack of new bags (3) close to the machine. The movable plate (11) is closed down on to the bag using a jack (12). Suction nozzles (10) hold the bag against the plates (8,11) so that the mouth of the bag is held open when the plates (8,11) are opened out again above the handle attachment station. A jack operated (18) feeder (4) lifts two half handles (5) from sloping supply rails (7). The handles are lifted up inside the bag mouth where they are welded in place using two retractable heated platens (19). After the handles are attached, the feeder (2) rotates, the suction on plates 8 and 11 is turned off and the completed bag is jettisoned on to a colelction table (21). ADVANTAGE - The productivity and cost of attaching handles to carrier bags is geratly increased using this automatic or semi-automatic machine.
Patent FR-2614036-A1 (FR)
Inventor: CHAVANNES JEAN-PIERRE
IPC: C11D3/42
Filed: 1988-04-13
Abstract: A bleach-free detergent composition contains from 0.1 to 5% by weight of a water-soluble salt of a polymeric  alpha -hydroxyacrylic acid as a bleach substitute. In particular, such a composition also contains an anionic optical brightener as well as a cationic softener. The composition can be liquid or in powder form.
Patent FR-2630681-A1 (FR)
Title: Axle for a vehicle with independent wheels in which the braking devices are remote from the wheels
Inventor: JEANSON RENE HENRI
IPC: B60G7/04
Filed: 1988-04-29
Abstract: The present invention relates to an axle for a vehicle including independent wheels 1 associated with braking devices 2 each one comprising a rotary part 3 and a stationary part 4. This axle is essentially characterized in that it comprises two coaxial half shafts 5 carrying at least one wheel 1 at each of their furthest-away ends, and the rotary part 3 of a braking device 2 at each of their closest ends, these half shafts being mounted rotationally in two sleeves 7 each one carrying the stationary part 4 of one of the braking devices 2 and each one secured to a suspension arm.
Patent FR-2632156-A1 (FR)
Title: Articulated-arm/hopper-support assembly for poultry force-feeder
IPC: A01K39/06
Filed: 1988-06-07
Abstract: The subject of the invention is a novel device which makes it possible to prevent the rotation of the hopper of all types of electrical force-feeders, and to protect and hold in the correct attitude the transmission assembly already existing. The assembly consists of the elements 10, 12 and 15 assembled by spindles 9 with two upper lugs 6, fixed to the framework 8, and two lower lugs 18, fixed to the support of the hopper 24. The articulations constituted by the spindles 9 allow the existing transmission assembly to be held in the correct operating attitude, whatever the position of the hopper 26. The articulated-arm/hopper-support assembly thus connected to the framework 8 cannot be driven by the rotational movement of the dispensing screw 25 when the hopper is filled with grain. The device according to the invention is intended in particular to be installed on electrical force-feeders of any model.
Patent FR-2619769-A1 (FR)
Title: Vehicle for the transportation of support frameworks for packets of glass
IPC: B62D61/12
Filed: 1988-08-26
Abstract: The packets 18 of glass are fixed via a plurality of devices shaped into tilting members 21 capable of being pressed against the packets of glass by means of an arm 22 in the shape of an L and of a supporting thrust cylinder 23, 24, these two members being connected to the longeron of the chassis in question of the vehicle, and all the supporting thrust cylinders being connected to a hydraulic circuit for operating in a corresponding way.
Patent FR-2620689-A1 (FR)
Title: Method for forming groups of products and for accompanying them towards a transfer line and device for implementing this method
Inventor: ZUCCHINI MAURO
IPC: B65B23/14
Filed: 1988-09-12
Abstract: The method provides for the use of at least two elements with clamps 6, 7 which are movable, in phase, and provided with alternating movements which are opposite to one another, or, alternatively, which follow one another in a continuous cycle, along the channel or line 2 where the products P, backing onto one another, are displaced or displace themselves towards a line 3 for transfer of groups GP of the same products P in work or subsequent removal stations; the said elements with clamps 6, 7 act in the direction of gripping, via each group, the first P' of the products P of desired groups in succession and they displace themselves, in the conveying direction of the products P, towards the said transfer line 3, substantially at the same speed of advance as the latter, until they are brought, one after the other, to bear against an accompanying element 11 which, at a higher speed than that of advance of the products P which are located upstream, accompanies them on the said transfer line 3.
Patent FR-2640097-A1 (FR)
Title: Procede de securisation des trains auxiliaires inseres-extraits dans une station quelconque le long d'une artere hertzienne numerique
Inventor: PERUYERO MICHEL
IPC: H04B17/40
Filed: 1988-11-16
Abstract: L'invention concerne un procédé de sécurisation de trains auxiliaires insérés-extraits dans une station quelconque le long d'une artère hertzienne numérique, dans lequel on effectue un calcul de redondance sur le signal principal, dans chacune des stations intermédiaires, afin d'élaborer des informations de qualité bond par bond que l'on retransmet dans la trame hertzienne afin de récupérer en tout point de la liaison hertzienne les informations de qualité de tous les bonds en amont. Application notamment au domaine des faisceaux hertziens.
Patent FR-2639434-A1 (FR)
Title: Methode et dispositif d'analyse d'un fluide polyphasique en ecoulement dans une conduite
Inventor: CASTEL YVON
IPC: G01N33/28
Filed: 1988-11-23
Abstract: La méthode d'analyse d'un fluide polyphasique en écoulement dans une conduite 9, 11, 15, 16, 18, est notamment caractérisée en ce que l'on effectue les étapes suivantes : - on dérive l'écoulement vers une chambre de puisage 28 pendant le temps nécessaire à son remplissage, - la chambre 28 étant remplie, on rétablit l'écoulement dans ladite conduite 9, 11, 15, 16, 18, - on produit une décantation du fluide situé dans la chambre 28, jusqu'à obtenir une séparation des différentes phases 70, 71, 72 qui composent le fluide, - on détermine un paramètre représentatif du volume d'au moins une phase, en mesurant une caractéristique sensible à la variation de composition d'au moins deux phases du fluide, et - on contrôle un paramètre macroscopique rendant compte de la qualité du fluide dans son ensemble, pendant le remplissage de la chambre de puisage et avant et/ou après le remplissage de la chambre 28. Le dispositif permet la mise en oeuvre de la méthode. L'invention s'applique notamment au domaine pétrolier, notamment à la production et au transport des effluents dans les régions difficiles d'accès.
Patent FR-2639875-A1 (FR)
Title: Machine d'impression d'objets a axe d'impression fixe
Inventor: DUBUIT JEAN-LOUIS
IPC: B41F15/08
Filed: 1988-12-05
Abstract: Il s'agit d'une machine d'impression du genre comportant un ensemble mobile 10 susceptible de porter un moyen d'impression plan, des moyens de rotation aptes à pivoter sur eux-mêmes, autour d'un axe d'impression fixe 0, au contact dudit moyen d'impression, l'objet à imprimer, des moyens de correction aptes à corriger simultanément la distance entre ledit moyen d'impression et ledit axe d'impression 0, et des moyens de transmission 11 établis entre lesdits moyens de rotation et un axe d'entraînement A propre à la commande de ceux-ci. Suivant l'invention, lesdits moyens de transmission A sont aptes à assurer au moins deux rapports de transmission différents. Application à l'impression d'objets de section transversale oblongue ou d'objets de section transversale circulaire.
Patent FR-2642231-A1 (FR)
Title: Improvements to electrical connectors
Inventor: EGON PHILIPPE ETIENNE RAPHAEL
IPC: H01R13/645
Filed: 1989-01-25
Abstract: Improvements to electrical connectors of the type of those which include two parts 1 and 2, one of which includes fingers engaging in centring sockets of the other part, characterised in that means are provided to allow lateral movement of one 1 of the parts in relation to the other 2 in a direction perpendicular to the longitudinal axis X-Y of the connector. The sockets 5, which extend beyond the face of the corresponding part, penetrate and are guided into oblong cavities provided on the other part.
Patent FR-2636966-A1 (FR)
Title: Production of the organic proteocrystal "chrysoeverine"
IPC: A61K35/63
Filed: 1989-02-20
Abstract: An organic proteocrystal derived, by biotechnological engineering, from the species Samia cyntia, which communicates antigrowth characteristics to certain human pathogenic conditions. The crystal is proposed as basis for the pharmaceutical manufacture of antineoplastic and antiviral agents. The crystal is well tolerated in human systems and does not interact with homeo tissue. The mechanism of action of the crystal occurs at the genetic level by causing the stop in the growth of certain oncological and viral processes. This process also systematically stimulates the production of genetic agents in order to produce an autovaccination capacity. This crystal is cruciform and exhibits a rare quality of quadripolarity. Other uses include a filtering agent for free radicals and other antigens and as base substance for research relating to the nature of growth factors, anti growth factors, factors for genetic alteration and the nature of cell polarity.