Round Side Research Articles

Prioritizing customer requirements for men’s denim jeans through factor analysis and fuzzy analytic hierarchy process

PurposeThe main purpose of this paper is to identify, screen and prioritize customer requirements (CRs) for men’s denim jeans. Moreover, the effect of demographic factors on the primary evaluation criteria has been examined.Design/methodology/approachThe study was initiated by the growing complaints about denim jeans products of a local manufacturing company. First, 24 CRs were identified from the literature and customer complaints. Then, a survey was conducted to rate the identified CRs and solicit more CRs through closed-ended and open-ended questions, respectively. From the survey, 368 usable responses were collected while the participants were shopping in 14 local retail shops. After analyzing the data using factor analysis, univariate and multivariate analysis of variance (MANOVA), and content analysis, the resulting 15 criteria were prioritized by experts’ pairwise comparisons employing the fuzzy analytic hierarchy process (AHP).FindingsFactor analysis extracted six components (primary criteria) including design cues, pocket design, comfort, size and fit, fashionability, and extrinsic cues from the CRs included in the closed-ended questions. MANOVA showed that age and frequency of purchasing denim jeans significantly affected the primary criteria, while educational level and frequency of wearing denim jeans did not. The weights from the fuzzy AHP revealed that colour fastness, price, durability, fabric weight, workmanship, side pocket design and fit as the most important CRs. Moreover, consumers preferred regular fit, stitched round side pockets, patch back pockets and stretchable denim fabric.Research limitations/implicationsThe limitations of the study are discussed in the body of the paper in Section 7.Originality/valueThe paper presents exploratory findings on denim jeans evaluation criteria in a developing country’s context. Moreover, the application of fuzzy AHP for prioritizing denim jeans’ CRs is unique.

INTERIOR IN THE ARCHITECTURE OF TRYPILLIA-CUCUTENI CULTURAL COMPLEX (problems of studies, interpretations and reconstructions)

The interior of Trypillian houses is not as available object as the interior of the folk architecture to which it actually belongs. The necessary steps to study the interior of Copper Age houses from archeological sites are:
 
 field research and advanced fixation in field documentation of detected interior details / remains;
 interpretation of discovered archaeological data;
 reconstruction of identified structural elements — the ultimate goal of the study which can be carried out on the basis of the interpretation of archeological objects using the method of study of buildings used by ethnology.
 
 It is necessary to take into account the sacral load of all elements of the dwelling, as well as the factor of transformation of them in the final stage of the settlement’s life into a ritual object. Formally, the following clay interior details can be distinguished: I — various enhancements, including rectangular and round elevations, side elevations, cruciform elevations, and catwalks; II — special clay storage tanks; III — furnaces.
 The analysis of the interior of Cucuteni—Trypillya dwellings shows the unity of the architectural tradition from the early up to the final stages. The origins of these traditions are related to the interior and ritual sphere of dwellings and settlements discovered in the oldest Neolithic Cultures of Europe. Clay interior details are characteristic of the architecture of the neo-neolithic crops of South-Eastern Europe. They are especially often recorded in buildings that were burned in ritual fires. Clay interior designs including in the form of rectangular and circular elevations are recorded in buildings of such cultures as Hamangia III, Boyan, Vedastra, different variants and periods of Vinca Culture. The rituals, similar to Trypillian ones, associated with rituals, known in the cultures of Tisza, Kojaderman-Karanovo-Gumelnitsa, Selkutsa.

Regulation of dynamic postural control to attend manual steadiness constraints.

In daily living activities, performance of spatially accurate manual movements in upright stance depends on postural stability. In the present investigation, we aimed to evaluate the effect of the required manual steadiness (task constraint) on the regulation of dynamic postural control. A single group of young participants ( n = 20) were evaluated in the performance of a dual posturo-manual task of balancing on a platform oscillating in sinusoidal translations at 0.4-Hz (low) or 1-Hz (high) frequencies while stabilizing a cylinder on a handheld tray. Manual task constraint was manipulated by comparing the conditions of keeping the cylinder stationary on its flat or round side, corresponding to low and high manual task constraints, respectively. Results showed that in the low oscillation frequency the high manual task constraint led to lower oscillation amplitudes of the head, center of mass, and tray, in addition to higher relative phase values between ankle/hip-shoulder oscillatory rotations and between center of mass/center of pressure-feet oscillations as compared with values observed in the low manual task constraint. Further analyses showed that the high manual task constraint also affected variables related to both postural (increased amplitudes of center of pressure oscillation) and manual (increased amplitude of shoulder rotations) task components in the high oscillation frequency. These results suggest that control of a dynamic posturo-manual task is modulated in distinct parameters to attend the required manual steadiness in a complex and flexible way. NEW & NOTEWORTHY We evaluated dynamic postural control on a platform oscillating in sinusoidal translations at different frequencies while performing a manual task with low or high steadiness constraints. Results showed that high manual task constraint led to modulation of metric and coordination variables associated with greater postural stability. Our findings suggest that motor control is regulated in an integrative mode at the posturo-manual task level, with reciprocal interplay between the postural and manual components.

The effects of cognitive versus motor demands on postural performance and weight bearing asymmetry in patients with stroke.

While several studies have investigated the interaction between postural control and secondary cognitive tasks in stroke patients, little is known about the influence of secondary motor task on postural control in these patients. The current research was designed to further examine dual-task performance by comparing the effects of cognitive versus motor dual-tasks on postural performance and weight bearing asymmetry (WBA) in stroke patients (n=23) relative to healthy, matched controls (n=22). All participants stood on dual-force plate under 5 conditions: (1) free standing; (2) simple cognitive task (easy Stroop) while standing; (3) difficult cognitive task (difficult Stroop) while standing; (4) simple motor task (holding a tray while a cylinder lying on its flat side) while standing; and (5) difficult motor task (holding a tray while a cylinder lying on its round side) while standing. The center of pressure (COP) measures was greater in stroke patients than healthy controls. Also, the WBA of the patients was greater than the controls. The COP measures increased when moving from single-task to cognitive dual-task conditions. No significant effect of motor dual-tasking was seen when moving from single-task to motor dual-task conditions. However, in contrast to cognitive dual-tasking, stroke patients and healthy controls employed different strategies during simultaneous performance of postural and motor tasks. It can be suggested that performing a motor task while standing requires greater attentional resources compared to performing a cognitive task while standing and this resulted in greater dual-task interference on motor performance in the stroke patients.

Higher order balance control: Distinct effects between cognitive task and manual steadiness constraint on automatic postural responses

In the present experiment, we aimed to evaluate the interactive effect of performing a cognitive task simultaneously with a manual task requiring either high or low steadiness on APRs. Young volunteers performed the task of recovering upright balance following a mechanical perturbation provoked by unanticipatedly releasing a load pulling the participant’s body backwards. The postural task was performed while holding a cylinder steadily on a tray. One group performed that task under high (cylinder’ round side down) and another one under low (cylinder’ flat side down) manual steadiness constraint. Those tasks were evaluated in the conditions of performing concurrently a cognitive numeric subtraction task and under no cognitive task. Analysis showed that performance of the cognitive task led to increased body and tray displacement, associated with higher displacement at the hip and upper trunk, and lower magnitude of activation of the GM muscle in response to the perturbation. Conversely, high manual steadiness constraint led to reduced tray velocity in association with lower values of trunk displacement, and decreased rotation amplitude at the ankle and hip joints. We found no interactions between the effects of the cognitive and manual tasks on APRs, suggesting that they were processed in parallel in the generation of responses for balance recovery. Modulation of postural responses from the manual and cognitive tasks indicates participation of higher order neural structures in the generation of APRs, with postural responses being affected by multiple mental processes occurring in parallel.

Sa1405 A Prospective Randomized Trial Comparing the 22-Gauge Needle With and Without a Side Port for Endoscopic Ultrasound Fine Needle Aspiration of Solid Pancreatic Mass Lesions

Sa1405 A Prospective Randomized Trial Comparing the 22-Gauge Needle With and Without a Side Port for Endoscopic Ultrasound Fine Needle Aspiration of Solid Pancreatic Mass Lesions Hirotoshi Ishiwatari*, Tsuyoshi Hayashi, Hiroshi Kawakami, Hiroyuki Isayama, Takao Itoi, Hiroyuki Hisai, Michihiro Ono, Yoko Abe, Natsuyo Yamamoto, Fumihide Itokawa, Tadashi Hasegawa Department of Medical Oncology and Hematology, Sapporo Medical University School of Medicine, Sapporo, Japan; Department of Gastroenterology and Hepatology, Hokkaido University Graduate School of Medicine, Sapporo, Japan; Department of Gastroenterology, The University of Tokyo, Tokyo, Japan; Department of Gastroenterology and Hepatology, Tokyo Medical University, Tokyo, Japan; Department of Gastroenterology, Japanese Red Cross Date General hospital, Date, Japan; Department of Surgical Pathology, Sapporo Medical University School of Medicine, Sapporo, Japan Background: Endoscopic ultrasound fine needle aspiration (EUS-FNA) is widely used for obtaining specimens from pancreatic mass lesions, owing to its high diagnostic accuracy, safety, and low invasiveness. However, it remains imperfect and needs modification to enable accurate diagnosis. The 22-gauge (G) fine needle aspiration (FNA) needle is widely used owing to its maneuverability. However, a 19G needle is superior in terms of tissue acquisition. To overcome this limitation, 22G FNA needles with a lateral side port have been developed. The side ports initially had a reverse beveled edge. Recently, needles with a round side port have been developed, which may reduce tissue damage and blood contamination, and improve diagnostic yield. Preliminary results have shown high diagnostic accuracy. We compared 22G FNA needles with and without a side port in pancreatic mass lesions in a multicenter prospective randomized control trial. Patients and Method: Between January and September 2013, consecutive 160 patients with a suspected solid pancreatic mass in five tertiary referral centers were enrolled. Patients were randomized to 22G FNA needle (EZ Shot 2, Olympus Medical Systems) with and without a side port groups (with and without groups, respectively). The primary endpoint was diagnostic accuracy. The secondary endpoints were adequacy of tissue acquisition and quality of the histological specimen (degree of contamination and amount of blood). Evaluations were made using a scoring system, by experienced attending pathologists, who were blinded to the clinical information, including the needle type. Results: Analysis of 158 patients (79 per group) was performed. Two patients did not undergo EUS-FNA after allocation. In four patients (three in the with group and one in the without group), EUS-FNA failed owing to difficulty of the puncture. There was no significant difference in the diagnostic accuracy rate (with group, 92.4% (73/79) vs. without group, 86.1% (68/79); P Z 0.3, Fisher’s exact test). In subgroup analysis, trainees (endosonographers with experience of fewer than 40 EUS-FNAs) had diagnostic accuracy rates of 97.4% (37/38) and 81.4% (35/43) in the with and without groups, respectively (P Z 0.03, Fisher’s exact test). Adequate samples for histological diagnosis were obtained in 61.3% (47/76) and 44.2% (34/78) of patients from the with and without groups, respectively (P Z 0.03, Fisher’s exact test). No significant difference was seen in the degree of sample contamination and amount of blood between the groups. Conclusion: There was no significant difference in diagnostic accuracy between the needle types. However, the needle with a side port allowed trainees to obtain the correct diagnosis at a higher rate. Moreover, the needle with a side port is superior for tissue acquisition.(Clinical trial registration number: UMI08120)

Aging increases flexibility of postural reactive responses based on constraints imposed by a manual task

This study compared the effect of stability constraints imposed by a manual task on the adaptation of postural responses between 16 healthy elderly (mean age = 71.56 years, SD = 7.38) and 16 healthy young (mean age = 22.94 years, SD = 4.82) individuals. Postural stability was perturbed through unexpected release of a load attached to the participant’s trunk while performing two versions of a voluntary task: holding a tray with a cylinder placed with its flat side down (low constraint) or with its rolling round side down (high constraint). Low and high constraint tasks were performed in alternate blocks of trials. Results showed that young participants adapted muscular activation and kinematics of postural responses in association with previous experience with the first block of manual task constraint, whereas the elderly modulated postural responses based on the current manual constraint. This study provides evidence for flexibility of postural strategies in the elderly to deal with constraints imposed by a manual task.

Role of Surface to Volume Ratio of Zinc Oxide Arrester Blocks on the Energy Absorption Capability

The functional life of a zinc oxide arrester block is largely dependent on its energy absorption capability. This capability is an important performance characteristic of a lighting arrester which leads to enhanced reliability of a surge protection system. An arrester block is usually cylindrical in shape with two flat surfaces. Injected energy of transient electrical surge into the arrester body is transformed into heat and dissipated through the surface of the disc body. This study has been conducted to observe whether the higher surface to volume (S/V) ratio of an arrester block enhances the capability of energy absorption or not. The round side or C-surface of the cylindrical disc was ground by diamond wheel to transform into hexagonal shape. By making the modification of the geometrical shape an increase of about 11% in S/V ratio was achieved. ZnO arrester blocks of both shapes were tested for energy. The average energy absorption capability for the hexagonal discs was found to be 483 J.cm−3 compared to that of 357 J.cm−3 for the discs having the cylindrical shape. Thus, about 35% increase in energy absorption capability is observed for the hexagonal discs. This knowledge can be useful in designing the geometry of the device for improved functional reliability of electrical system.

Keeping your balance while balancing a cylinder: interaction between postural and voluntary goals

The present study investigated whether postural responses are influenced by the stability constraint of a voluntary, manual task. We also examined how task constraint and first experience (the condition with which the participants started the experiment) influence the kinematic strategies used to simultaneously accomplish a postural response and a voluntary task. Twelve healthy, older adults were perturbed during standing, while holding a tray with a cylinder placed with the flat side down (low constraint, LC) or with the rolling, round side down (high constraint, HC). Central set changed according to the task constraint, as shown by a higher magnitude of both the gastrocnemius and tibialis anterior muscle activation bursts in the HC than in the LC condition. This increase in muscle activation was not reflected, however, in changes in the center of pressure or center of mass displacement. Task constraint influenced the peak shoulder flexion for the voluntary tray task but not the peak hip flexion for the postural task. In contrast, first experience influenced the peak hip flexion but not the peak shoulder flexion. These results suggest an interaction between two separate control mechanisms for automatic postural responses and voluntary stabilization tasks.

The interaction of postural and voluntary strategies for stability in Parkinson's disease.

This study assessed the effects of stability constraints of a voluntary task on postural responses to an external perturbation in subjects with Parkinson's disease (PD) and healthy elderly participants. Eleven PD subjects and twelve control subjects were perturbed with backward surface translations while standing and performing two versions of a voluntary task: holding a tray with a cylinder placed with the flat side down [low constraint (LC)] or with the rolling, round side down [high constraint (HC)]. Participants performed alternating blocks of LC and HC trials. PD participants accomplished the voluntary task as well as control subjects, showing slower tray velocity in the HC condition compared with the LC condition. However, the latency of postural responses was longer in the HC condition only for control subjects. Control subjects presented different patterns of hip-shoulder coordination as a function of task constraint, whereas PD subjects had a relatively invariant pattern. Initiating the experiment with the HC task led to 1) decreased postural stability in PD subjects only and 2) reduced peak hip flexion in control subjects only. These results suggest that PD impairs the capacity to adapt postural responses to constraints imposed by a voluntary task.

Numerical Investigation of Effect of Bridge Pier Shape on Dynamic Forces

The flow around bluff bodies is a subject of much concern to several researchers. The pier shape effects on flow pattern, vorticities and shedding in the wake region and corresponding fluid forces acting to bridge piers. There are fewer studies about appropriate shape of pier to reduce dynamic forces. In this research, two dimensional water flow around different common shapes of pier was simulated using FLUENT at Reynolds number 2×105, and the effect of pier shape on the drag and lift coefficients was studied. Also drag and lift forces in the case of the inclined pier subjected to flow was studied. The main object of research is obtaining the appropriate shape for reducing cross forces. Finally the investigation showed that rectangular pier with round and sharp nose in the case of round side flow had better performance in both straight and inclined flow and less dynamic forces.

Ladder webs in orb-web spiders: ontogenetic and evolutionary patterns in Nephilidae

Spider web research bridges ethology, ecology, functional morphology, material science, development, genetics, and evolution. Recent work proposes the aerial orb web as a one-time key evolutionary innovation that has freed spider-web architecture from substrate constraints. However, the orb has repeatedly been modified or lost within araneoid spiders. Modifications include not only sheet- and cobwebs, but also ladder webs, which secondarily utilize the substrate. A recent nephilid species level phylogeny suggests that the ancestral nephilid web architecture was an arboricolous ladder and that round aerial webs were derived. Because the web biology of the basalmost Clitaetra and the derived Nephila are well understood, the present study focuses on the webs of the two phylogenetically intervening genera, Herennia and Nephilengys, to establish ontogenetic and macroevolutionary patterns across the nephilid tree. We compared juvenile and adult webs of 95 Herennia multipuncta and 143 Nephilengys malabarensis for two measures of ontogenetic allometric web changes: web asymmetry quantified by the ladder index, and hub asymmetry quantified by the hub displacement index. We define a ‘ladder web’ as a vertically elongated orb exceeding twice the length over width (ladder index ≥ 2) and possessing (sub)parallel rather than round side frames. Webs in both genera allometrically grew from orbs to ladders, more so in Herennia. Such allometric web growth enables the spider to maintain its arboricolous web site. Unexpectedly, hub asymmetry only increased significantly in heavy-bodied Nephilengys females, and not in Herennia, challenging the commonly invoked gravity hypothesis. The findings obtained in the present study support the intrageneric uniformness of nephilid webs, with Herennia etruscilla webs being identical to H. multipuncta. The nephilid web evolution suggests that the ancestor of Nephila reinvented the aerial orb web because the orb arises at a much more inclusive phylogenetic level, and all intervening nephilids retained the secondarily acquired substrate-dependent ladder web.

G0700-2-3 直動式動弁機構カム・フォロワの摩擦特性に関する研究(エンジンシステム部門一般講演(2))

Some studies to reduce the friction of valve train mechanism have been conducted in order to prevent the global warming by improving the fuel economy for internal combustion engines. In the case of the contact between the cam and the shim offset on the valve lifter for the direct-type valve train, the characteristics of friction diagrams measured with the cam / slipper follower friction tester were examined and also the oil film thickness between the valve lifter and the shim was predicted by the hydrodynamic lubrication theory so that the followings have been summarized, (1) The friction of rolling contact between cam and follower becomes considerably small because the shim offset on the valve lifter rotates under the contact of cam. (2) The thickness of oil film with the round side face or the flat bottom face of the shim is enough to make the shim to rotate on the vale lifter.

Free fatty acid profile of Parmigiano–Reggiano cheese throughout ripening: Comparison between the inner and outer regions of the wheel

From each of twenty wheels of Parmigiano–Reggiano cheese of different ages (1–24 months), samples representative of the inner part (I, 10 cm from the round side and 7 cm from the flat side) and of the outer part (O, the rest of the cheese after removing the rind) were collected. For each sample, free fatty acids (FFAs, expressed as mg kg −1 cheese fat) were determined by quantitative capillary gas chromatography. In 18- and 24-month-old cheese, total levels of FFAs (as sum of individual FFAs) were significantly ( P ≤ 0.05) higher in O than I, whereas no differences between regions were observed in 1-, 6- and 12-month-old cheeses. In terms of short (C4–C8) and medium (C10–C14) chain FFAs, levels in the outer regions were higher ( P ≤ 0.05) than inner regions for cheeses from 6- to 24-month-old. The content of long-chain FFAs (C16–C18:2) was higher in O than I in 18- and 24-month-old cheeses.

Stacking of blocks by chimpanzees: developmental processes and physical understanding

The stacking-block task has been used to assess cognitive development in both humans and chimpanzees. The present study reports three aspects of stacking behavior in chimpanzees: spontaneous development, acquisition process following training, and physical understanding assessed through a cylindrical-block task. Over 3 years of longitudinal observation of block manipulation, one of three infant chimpanzees spontaneously started to stack up cubic blocks at the age of 2 years and 7 months. The other two infants began stacking up blocks at 3 years and 1 month, although only after the introduction of training by a human tester who rewarded stacking behavior. Cylindrical blocks were then introduced to assess physical understanding in object-object combinations in three infant (aged 3-4) and three adult chimpanzees. The flat surfaces of cylinders are suitable for stacking, while the rounded surface is not. Block manipulation was described using sequential codes and analyzed focusing on failure, cause, and solution in the task. Three of the six subjects (one infant and two adults) stacked up cylindrical blocks efficiently: frequently changing the cylinders' orientation without contacting the round side to other blocks. Rich experience in stacking cubes may facilitate subjects' stacking of novel, cylindrical shapes from the beginning. The other three subjects were less efficient in stacking cylinders and used variable strategies to achieve the goal. Nevertheless, they began to learn the effective way of stacking over the course of testing, after about 15 sessions (75 trials).

On the deposition of Cr 3−δO 4 spinel particles upon laser-heated pedestal growth of Cr:YAG fiber

The microstructures of Cr 4+:YAG crystal fibers grown along [1 1 1] direction by laser-heated pedestal growth method were studied by optical and analytical electron microscopy. Curved growth ledges were found on the round side surface of the fiber grown at a relatively high speed. In contrast, nonepitaxial Cr 3− δ O 4 crystallites with spinel-type structure were formed on the {1 1 2} side surfaces, via an intermediate surface melt, when the fibers were grown at a lower speed. The deposition of Cr 3− δ O 4, rather than segregation of Cr and Ca codopants, as of concern to the Cr 4+ fluorescence, can be rationalized by a high crystal field stabilization of octahedrally coordinated Cr 3+ attained in rather refractory and close packed oxide.

Automatic Design of 3-D Fixtures and Assembly Pallets

This paper presents an implemented algorithm that automatically de signs fixtures and assembly pallets to hold three-dimensional parts. All fixtures generated by the algorithm employ round side locators, a side clamp, and cylindrical supports; depending on the value of an input-control flag, the fixture may also include swing-arm top clamps. Using these modular elements, the algorithm designs fix tures that rigidly constrain and locate a part, obey task constraints, are robust to part-shape variations, are easy to load, and are eco nomical to produce. For the class of fixtures that are considered, the algorithm is guaranteed to find the global optimum design that sat isfies these and other pragmatic conditions. We present the results of the algorithm applied to several practical manufacturing problems. For these complex problems, the algorithm typically returns initial high-quality fixture designs in less than a minute, and identifies the global optimum design in just over an hour. The algorithm is also capable of solving difficult design problems where a single fixture is desired that can hold either of two parts.

Hydrodynamical Comparison of Aortic Arch Cannulae

The high velocity of blood flow exiting aortic arch cannulae may erode atherosclerotic material from the aortic intima causing non-cardiac complications such as stroke, multiple organ failure and death. Five 24 Fr cannulae from the Sarns product line (straight open tip, angled open tip with and without round side holes, straight and angled closed tip with four rectangular, lateral side holes), and a flexible cannula used at the University Hospital of Gent (straight open tip) are compared in an in vitro steady flow setup, to study the spatial velocity distribution inside the jet. The setup consists of an ultrasound Doppler velocimeter, mounted opposite to the cannula tip in an outflow reservoir. An elevated supply tank supplies steady flow of 1.3 L/min of water. Exit forces at various distances from the tip are calculated by integrating the assessed velocity profiles. The pressure drop across the cannula tip is measured using fluid filled pressure transducers. The four sidehole design provides the lowest exit velocity (0.85 versus 1.08 m/s) and force per jet (0.03 vs 0.15-0.20 N). The round sideholes are useless as less than 1% of the flow is directed through them. Furthermore, the use of angled tip cannulae is suggested because the force exerted on the aortic wall decreases the more the angle of incidence of the jet deviates from 90 degrees. Pressure drop is the lowest for the 4 side hole design and highest for the open tip and increases when an angled tip is used.

A chaperonin from a thermophilic bacterium, Thermus thermophilus

Unlike Escherichia coli chaperonins, a chaperonin (cpn) from a therm ophilic bacterium , Thermus thermophilus , consisting of homologues to GroEL (cpn 60) and GroES (cpn 10) is co-purified as a large complex. Thermus chaperonin shows a bullet-like shape in the side view seen by electron microscopy, and antibody against cpn 10 binds only to the round side of the bullet. We conclude that a single cpn 60-heptam er ring with two stripes stacks into two layers and a cpn 10 oligomer binds to one side of the layers. The purified Thermus chaperonin contains endogenously bound ADP, and incubation with ATP causes a partial dissociation of chaperonin into cpn 60 monomers and a cpn 10 heptam er. The effect of Thermus chaperonin on protein refolding upon dilution from guanidine HCl is different at three temperature ranges. At high temperatures above 55°C, where the native proteins are stable but their spontaneous foldings fail, the chaperonin induces productive folding in an ATP-dependent manner. At middle temperatures (25-55°C) where spontaneous foldings of the enzymes occur, the chaperonin slows down the rate of folding without changing the final yield of productive folding. At lower temperatures below 25°C where spontaneous foldings also occur, the chaperonin arrests the folding even in the presence of ATP. When a solution of relatively heat labile protein is incubated at high temperatures, and then residual activity of the protein is measured at its optimal temperature after incubation with ATP, the temperature that causes irreversible heat denaturation of the protein is elevated about 10°C by inclusion of Thermus chaperonin in the solution. Furthermore, once the folding intermediate of a protein is captured by Thermus chaperonin, it retains the ability to resume productive folding even after exposure to the otherwise denaturing high temperature. These results indicate that during heat denaturation proteins assume the common structure which is recognizable by the chaperonin. Finally, a ‘folding intermediate reservoir’ model to explain the effect of chaperonin is proposed, and is compared with a ‘marsupium ’ model.

Structure of holo-chaperonin studied with electron microscopy Oligomeric cpn10 on top of two layers of cpn60 rings with two stripes each

A structural model of holo-chaperonin, known as a protein-folding control protein comprising 60 kDa (cpn60) and 10 kDa polypeptides (cpn10), is proposed based on the electron microscopic images of holo-chaperonin from Thermus thermophilus and cpn60 from Paracoccus denitrificans. Isolated Paracoccus cpn60 shows very similar images to those of Escherichia coli tetradecameric cpn60, a seven-membered ring in the top view and a rectangular shape with four stripes in the side view. However, a small number of half-thick rectangles with two stripes are also seen which indicates that a single cpn60-heptamer ring has two stripes parallel to the plane of the ring. Thermus holo-chaperonin shows a bullet-like shape in the side view, and antibory against cpn10 binds only to the round side of the bullet. We conclude that a single cpn60-heptamer ring with two stripes stacks into two layers, and a cpn10 oligomer binds to one side of the layers.