Proprioception in Limulus

1956 ◽  
Vol 33 (4) ◽  
pp. 658-667
Author(s):  
J. W. S. PRINGLE

1. Tonic and phasic discharges of impulses may be recorded in the small leg nerve of Limulus from endings sensitive to the position and movement of the femorotibial and other joints. 2. The nerve fibres originate from the large sensory cells described by Stuart (1953). Of those at the femoro-tibial joint, one group of cells lies under the hinge and the endings react tonically to the strains present in the cuticle; some are excited by flexion and some by extension. The other group of cells, lying more internally, have endings in the connective tissue and react phasically only during joint movement. 3. The relationship is discussed between these endings and the lyriform organs of Arachnids and the campaniform sensilla of insects.

1967 ◽  
Vol 2 (3) ◽  
pp. 349-358
Author(s):  
R. M. EAKIN ◽  
JANE A. WESTFALL ◽  
M. J. DENNIS

The eye of a nudibranch, Hermissenda crassicornis, was studied by light and electron microscopy. Three kinds of cells were observed: large sensory cells, each bearing at one end an array of microvilli (rhabdomere) and at the other end an axon which leaves the eye by the optic nerve; large pigmented supporting cells; and small epithelial cells, mostly corneal. There are five sensory cells, and the same number of nerve fibres in the optic nerve. The receptor cells contain an abundance of small vesicles, 600-800 Å in diameter. The lens is a spheroidal mass of osmiophilic, finely granular material. A basal lamina and a capsule of connective tissue enclose the eye. In some animals the eye is ‘infected’ with very small bodies, 4-5 µ in diameter, thought to be symbionts.


1999 ◽  
Vol 354 (1380) ◽  
pp. 161-182 ◽  
Author(s):  
J. B. Messenger ◽  
J. Z. Young

This paper describes the ontogeny, breakdown and absorption of the radular teeth of cephalopods and, for the first time, considers the function of the ‘bolsters’ or radular support muscles. The radular ribbon, which bears many regularly arranged transverse rows of teeth one behind the other, lies in a radular canal that emerges from the radular sac. Here the radular teeth are formed by a set of elongate cells with microvilli, the odontoblasts. These are organized into two layers, the outer producing the radular membrane and the bases of the teeth, the inner producing the cusps. The odontoblasts also secrete the hyaline shield and the teeth on the lateral buccal palps, when these are present. At the front end of the radular ribbon the teeth become worn in feeding and are replaced from behind by new ones formed continuously in the radular sac, so that the whole ribbon moves forward during ontogeny. Removal of the old teeth is achieved by cells in the radular organs; these cells, which are formed from modified odontoblasts (‘odontoclasts’), dissolve the teeth and membranes and absorb them. There is a subradular organ in all cephalopods. In Octopus vulgaris , which bores into mollusc shells and crustacean carapaces, it is especially well–developed and there is also a supraradular organ. A characteristic feature of the cephalopod radular apparatus is the pair of large radular support muscles or ‘bolsters’. Their function seems never to have been investigated, but experiments reported here show that when they elongate, the radular teeth become erect at the bending plane and splayed, presumably enhancing their ability to rake food particles into the pharynx. The bolsters of Octopus function as muscular hydrostats: because their volume is fixed, contraction of their powerful transverse muscles causes them to elongate. In decapods and in nautiloids each bolster contains a ‘support rod’ of semi–fluid material, as well as massive transverse musculature. This rod may elongate to erect the radular teeth. At the extreme front end of the bolsters in Octopus there are many nerve fibres that may constitute a receptor organ signalling the movements of the radula against hard material. Such nerves are absent from decapods and from octopods that do not bore holes. The buccal mass of Nautilus is massive, with heavily calcified tips to the beaks and a wide radular ribbon, with 13 rather than nine elements in each row. Nevertheless all the usual coleoid features are present in the radular apparatus and the teeth are formed and broken down in the same way. However, Nautilus has a unique structure, the radular appendage. This comprises a papillate mass extending over the palate in the mid–line and forming paired lateral masses that are in part secretory. The organ is attached to the front of the radula by muscles and connective tissue. Its function is unknown.


2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 1249.2-1249
Author(s):  
S. Nakashima ◽  
T. Kameda ◽  
H. Shimada ◽  
M. Mahmoud Fahmy Mansour ◽  
R. Wakiya ◽  
...  

Background:Connective tissue disease-associated pulmonary hypertension (CTD-PH) is constructed by a variety of pathologies, including cardiac, pulmonary, and vascular involvement, as well as immune abnormalities. Because of its various constructs, it is difficult for many respiratory physicians, cardiologists, and rheumatologists to determine a treatment strategy for CTD-PH. In addition, CTD-PH has different pathologies from iPAH, and there are cases in which immunosuppressive therapy is effective. These suggests that the two PAHs may have different pathogenesis, including inflammation in the pulmonary artery. However, there are not enough biomarkers to distinguish pathologies. On the other hand, it has been reported that various cytokines such as TIMP-1, Interleukin (IL)-6, IL-17, and IL-21 are involved in the pathogenesis of CTD-PH or vasculitis. (1,2) However, the relationship between these cytokine expression and the pathogenesis or treatment of CTD-PH has not been fully clarified.Objectives:To clarify the relationship between cytokine profile and clinical features, change in cytokines and hemodynamics by treatment, association with the effectiveness of immunosuppressive therapy.Methods:Patients suspected PH was included. At the time of cardiac catheterization(RHC), sera in pulmonary pre and post-capillary were collected and TIMP-1, MCP-1, IL-17 and IL-21, IL-12p70 and IL-6 were analyzed by ELISA(ABCAM UK, Ella simple plex USA). The following clinical data were collected: age, gender, underlying disease, complication of interstitial lung disease, treatment (immunosuppressant and pulmonary vasodilator), hemodynamics. Furthermore, we investigated the relationship between cytokines and clinical data.Results:15 cases of CTD-PH, 13 cases of non-CTD-PH, and 6 cases of non-PH were analyzed. (SSc 12 cases, MCTD 7cases, SLE 2 cases, and others 13 cases) 28 cases were diagnosed with PH by RHC. There was a positive correlation between IL-6 and mean pulmonary arterial pressure in all PH case. In addition, MCP-1, IL-6, and TIMP-1 tend to be high in SSc-PH cases. On the other hand, in Non-SSc-PH, IL-12p70 and IL-17 were high. In cases who pulmonary vascular hemodynamics improved by treatment, IL-17, IL-21, and TIMP-1 decreased.Conclusion:Biomarker profiles in pulmonary capillaries may differ depending on the disease. Furthermore, it suggested that IL-17, IL-21 and TIMP-1 may be biomarkers of therapeutic effect.References:[1]Hashimoto-Kataoka T. et al. Proc Natl Acad Sci U S A. 2015 May 19;112(20):E2677-86.[2]Jun Ishizaki et al. Arthritis Res Ther. 2017 Sep 29;19(1):218.Disclosure of Interests:None declared.


1862 ◽  
Vol 152 ◽  
pp. 911-938 ◽  

In the Philosophical Transactions for 1859, I showed that, in the adult spinal cord of Man and all vertebrate animals, the white columns as well as the grey substance are everywhere interspersed with granular nuclei, of which some are attached to the sheaths of the primitive nerve-fibres, while others are imbedded in the intervening connective tissue. In the grey substance these nuclei are more abundant than in the white, and have much resemblance to many of the free nuclei or cells, which are certainly in connexion with nerve-fibres, and with which they are freely intermixed. With the hope of throwing some light on the histological relation between these and the other elemen­tary tissues of the cord, the following inquiries into their development were under­taken. The histology of the development of the spinal cord in Birds and the higher animals had already been begun by Bidder and Kupffer, and pursued a little further by Kölliker. The results of their investigations are comprised in the following statements:


Crisis ◽  
2011 ◽  
Vol 32 (5) ◽  
pp. 246-253 ◽  
Author(s):  
Gretchen E. Ely ◽  
William R. Nugent ◽  
Julie Cerel ◽  
Mholi Vimbba

Background: The relationship between suicidal thinking and adolescent dating violence has not been previously explored in a sample of adolescent abortion patients. Aims: This paper highlights a study where the relationship between dating violence and severity of suicidal thinking was examined in a sample of 120 young women ages 14–21 seeking to terminate an unintended pregnancy. Methods: The Multidimensional Adolescent Assessment Scale and the Conflict in Adolescent Relationships Scale was used to gather information about psychosocial problems and dating violence so that the relationship between the two problems could be examined, while controlling for the other psychosocial problems. Results: The results suggest that dating violence was related to severity of suicidal thinking, and that the magnitude of this relationship was moderated by the severity of problems with aggression. Conclusions: Specifically, as the severity of participant’s general problems with aggression increased, the magnitude of the relationship between dating violence and severity of suicidal thinking increased. Limitations of the study and implications for practice are discussed.


Author(s):  
Melanie K. T. Takarangi ◽  
Deryn Strange

When people are told that their negative memories are worse than other people’s, do they later remember those events differently? We asked participants to recall a recent negative memory then, 24 h later, we gave some participants feedback about the emotional impact of their event – stating it was more or less negative compared to other people’s experiences. One week later, participants recalled the event again. We predicted that if feedback affected how participants remembered their negative experiences, their ratings of the memory’s characteristics should change over time. That is, when participants are told that their negative event is extremely negative, their memories should be more vivid, recollected strongly, and remembered from a personal perspective, compared to participants in the other conditions. Our results provide support for this hypothesis. We suggest that external feedback might be a potential mechanism in the relationship between negative memories and psychological well-being.


1994 ◽  
Vol 72 (01) ◽  
pp. 058-064 ◽  
Author(s):  
Goya Wannamethee ◽  
A Gerald Shaper

SummaryThe relationship between haematocrit and cardiovascular risk factors, particularly blood pressure and blood lipids, has been examined in detail in a large prospective study of 7735 middle-aged men drawn from general practices in 24 British towns. The analyses are restricted to the 5494 men free of any evidence of ischaemic heart disease at screening.Smoking, body mass index, physical activity, alcohol intake and lung function (FEV1) were factors strongly associated with haematocrit levels independent of each other. Age showed a significant but small independent association with haematocrit. Non-manual workers had slightly higher haematocrit levels than manual workers; this difference increased considerably and became significant after adjustment for the other risk factors. Diabetics showed significantly lower levels of haematocrit than non-diabetics. In the univariate analysis, haematocrit was significantly associated with total serum protein (r = 0*18), cholesterol (r = 0.16), triglyceride (r = 0.15), diastolic blood pressure (r = 0.17) and heart rate (r = 0.14); all at p <0.0001. A weaker but significant association was seen with systolic blood pressure (r = 0.09, p <0.001). These relationships remained significant even after adjustment for age, smoking, body mass index, physical activity, alcohol intake, lung function, presence of diabetes, social class and for each of the other biological variables; the relationship with systolic blood pressure was considerably weakened. No association was seen with blood glucose and HDL-cholesterol. This study has shown significant associations between several lifestyle characteristics and the haematocrit and supports the findings of a significant relationship between the haematocrit and blood lipids and blood pressure. It emphasises the role of the haematocrit in assessing the risk of ischaemic heart disease and stroke in individuals, and the need to take haematocrit levels into account in determining the importance of other cardiovascular risk factors.


2014 ◽  
pp. 147-153
Author(s):  
P. Orekhovsky

The review outlines the connection between E. Reinert’s book and the tradition of structural analysis. The latter allows for the heterogeneity of industries and sectors of the economy, as well as for the effects of increasing and decreasing returns. Unlike the static theory of international trade inherited from the Ricardian analysis of comparative advantage, this approach helps identify the relationship between trade, production, income and population growth. Reinert rehabilitates the “other canon” of economic theory associated with the mercantilist tradition, F. Liszt and the German historical school, as well as a reconside ration of A. Marshall’s analysis of increasing returns. Empirical illustrations given in the book reveal clear parallels with the path of Russian socio-economic development in the last twenty years.


2020 ◽  
Vol 7 (2) ◽  
pp. 291-317
Author(s):  
Burak Çavuş

Bu çalışmada, 1960-1990 yılları arasında yayınlanan ve Avrupa’ya işçi göçünü konu edinen romanlar izleksel bağlamda incelenmiştir. Romanlardaki temel izlekler çerçevesinde göç süreci irdelenmiş, inceleme, göçmenlerin tanımlanmasında ve adlandırılmasında kullanılan Gastarbeiter (konuk işçi) Auslander (yabancı) kavramları ve Almanlar tarafından Türk kimliğine atfedilen çağrışımlar üzerinden yürütülmüştür. Göçmenlere yönelik politikalarda ve yaklaşımlarda onların nasıl tanımlandığının etkili olduğuna ve yazınsal süreçte de bu politika ve yaklaşımların belirleyici olduğu savından hareket edilmiştir. Bu noktada adlandırmaların, tanımlamaların göç olayı çerçevesinde biz ve öteki ilişkisi üzerindeki etkisine odaklanılmış; toplum ve yazın ilişkisi temelinde incelenen romanlar üzerinden göç ve göçmenlik meselesine dair çıkarımlar yapılmıştır. Bunlar arasında, ayrımcılık, kötü çalışma koşulları, hak ihlalleri, ırkçılık ve ötekileştirme gibi başat sorunların bu eserlerde merkezi konumda olduğu tespit edilmiştir. Böylece çalışmanın amacı olan göç yazınını oluşturan temel izleklere ulaşılmış; sosyolojik ve tarihsel gerçekliğin yazınsal gerçekliğe aktarılmasında etkili olan unsurlar ön plana çıkarılmıştır. ABSTRACT IN ENGLISH Main Patterns in Migration Novels In this study, the novels published between 1960-1990 and dealing with the migration of workers to Europe were examined in a contextual context. The process of immigration has been examined within the framework of the basic lines in the novels, through the concepts of Gastarbeiter (guest worker), Auslander (foreigner) used in the identification and naming of immigrants and connotations attributed to Turkish identity was conducted. The argument is that how they are defined is effective in policies and approaches towards immigrants and that these policies and approaches are determinative in the literary process. At this point, the effect of naming definitions on us and the other relationship within the framework of migration has been focused; there are inferences about the issue of migration and immigration through the novels examined on the basis of the relationship between society and literature. Among these, it has been determined that dominant problems such as discrimination, poor working violations, racism and marginalization are central to these works. Thus, the basic themes that constitute the migration literature, which is the aim of the study have been reached and the factors that are effective in transferring the sociological and historical reality have been brought the fore.


2020 ◽  
Vol 10 (1) ◽  
pp. 59-71
Author(s):  
Perrine Moran

Many couples who come for therapy are struggling with separating from unconscious phantasies and beliefs that enmesh each partner with the other, resulting in states that popular songs powerfully epitomise. While this borderline experience is common and functional in the early stages of being in love its persistence paralyses the development of the relationship. Facing separation from and loss of illusion is a challenge couple therapists are often asked to help with. The argument is illustrated by a case, and by references to some of Cole Porter’s best known songs.


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