Studies in immunity: more especially with reference to some of the reactions of complement; and, to the seat of origin of complement and immune body

#1. The method of investigating the seat of origin of antibodies, especially the haemolysins, bactericidal bodies and precipitins, by means of "Organ extracts" is valueless: and no reliance can be placed on results derived by such a method. #2. Normal rabbits, injected intravenously with ox blood corpuscles, show Immune body, in their blood, against ox blood corpuscles, for the first time, on or about the third day. #3. Normal rabbits, from which the spleen alone, the spleen and thyroid, the thyroid alone, or one Kidney has been removed and into which, within a week or so after the operation, ox blood corpuscles have been injected intravenously, show, like the controls, Immune body, against ox blood corpuscles * for the first time on or about the third day. #4. The total leucocyte count of perfectly normal rabbits may vary in different individuals between roughly 4,000 and 15,000; in individual rabbits, in ordinary and exaggerated conditions of laboratory life, as regards feeding time of day &c., the total leucocytes do not vary beyond 3,000 on either side of a mean per Cram,that is beyond the limits to be allowed for experimental error. #5. The differential count, as regards polymorphonuclears and lymphocytes, varies so much, under ordinary laboratory conditions, in the same rabbit, at different times, and in different rabbits, that conclusions should be drawn, with great caution, from any variation under experimental conditions. #6. The spleen was removed from a normal rabbit. Two days after its removal, it was injected intravenously with ox blood corpuscles. Immune body appeared in its blood in three days and yet there was no leucocytosis. To adopt the usual criterion this may be taken as evidence that a compensatory action on the part of the hone marrow and lymphatic apparatus has been excluded. #7. Injections into normal rabbits, intravenously, intraperitoneally, and subcutaneously, of even large amounts of ox blood corpuscles do not produce a variation in the total leucocyte count beyond that in control animals. #8. Such injections, - and I speak here with the greatest caution - produce no effect on the differential count. #9. From the above results, I would conclude provisionally, that so far as such methods can settle such a question, there is great probability that neither, the spleen, nor the bone marrow, nor the lymphatic apparatus, nor the kidney, is the seat of formation in rabbits, of Immune body against ox blood corpuscles. #10. Normal rabbits, from whom blood, a haemoiysin, agglutinin and precipitin for ox blood has been carefully excluded, after being fed for some time on ox blood, show in their blood all of these active principles. This gives some support to the view, to be advanced in this paper, that the formation of antibodies is allied to the ordinary physiological processes of assimilation: and as the liver is accredited by physiologists with a high role in such processes, to the liver being regarded provisionally as a possible seat of formation of Immune body, - (for sensitised ox blood corpuscles. #11. The amount of complement in leech, citrate, fluoride, and oxalate plasmas of the rabbit is the same as in the corresponding leech, citrate, fluoride, and oxalate sera. #12. Normal aqueous humour of rabbits and the fluid from a tape worm cyst of the rabbit, do not contain complement for sensitised ox blood corpuscles. They are both highly specialised secretions. #13. The fluid that collects in a short time after puncture in the anterior chamber of the eye and Blister fluids do contain, such complement. They are both of the nature of transudates from the blood vessels. #14. As showing the highly specialised nature of the secretion in the anterior chamber of the eye, some rabbits, with a blood serum, of very high titre in Immune body against ox blood corpuscles, may have none of this Immune body in even 0.5cc of their aqueous humour). #15. Normal rabbits may be bled to the extent of more than one third of their blood at one sitting, or of more than one half within 18 hours without showing any change in the complement content of their serum for sensitised ox blood corpuscles . #16. If a normal rabbit, whose blood has been ascertained to be free from Immune body against ox blood corpuscles, be injected intravenously with a large amount of ox blood corpuscles - 28cc equivalent to 56cc defibrinated blood - the ox blood corpuscles can be recognised in the rabbit's general circulation until about the third day. At that time there is a critical formation of Immune body, a critical disappearance of the ox blood corpuscles, and a critical haemoglobinuria. contrary to what Sachs found, I did not observe any variation in the complement content for ox blood corpuscles in such an experiment. #17. The infection intravenously into normal rabbits of unsensitised ox blood corpuscles, even in very large quantity, does not produce any diminution of complement. The injection intravenously into normal rabbits, of an amount of sensitised or saturated ox blood corpuscles calculated to be sufficient to use up all the complement in the rabbit's body produces no reduction of the complement, while the injection of four times the calculated amount of such corpuscles into a similar rabbit, produces a scarcely perceptible diminution of the complement. On the other hand, the injection intravenously into rabbits, which have been immunised against ox blood corpuscles, of a quantity of fresh, sensitised, or saturated corpuscles far from sufficient to use up all the calculated amount of complement in the animal's body, markedly reduces the complement content of the animal's blood. Such animals often die rapidly. The possible explanation of both Phenomena may be,that the sudden lysis sets free stromata, which absorb the complement and further block the capillaries of the lung and other organs. #18. If a normal rabbit be injected intraperitoneally with inactivated Immune serum against rabbit corpuscles, obtained by injecting a guinea pig with rabbit corpuscles, this heated immune serum appears to be absorbed into the rabbits bloodyto find complement there free in the blood, to unite with it and to cause extracellular haemolysis of the rabbi'ts red blood corpuscles and intense haemoglobinuria. #19. There is great probability therefore, that complement exists, free in the circulating plasma of the blood, and that, further, the organ, producing complement, must be one of great metabolic activity and of exceptional powers of regeneration. #20. The extirpation of the spleen and of the thyroid in rabbits may be said to cause no variation in the complement content of rabbits' serum. #21. Taking such things in relation, with the positive findings of Nolf, Ehrlich &c., I submit that the liver ought to be considered as a possible seat of origin of complement. #22. When hen corpuscles are injected intravenously into rabbits, the corpuscles tend to accumulate and to be retained in the liver. #23. Such corpuscles are phagocyted to a small degree by the liver cells and Kupfer cells. No evidence was observed for phagocytosis taking place in the spleen or any of the other organs. #24. The liver cells are capable of a wide variation in morphological appearance, possibly corresponding with a similar wide range of metabolic activity and functioning. #25. Taking into consideration the facts exclusive and presumptive accumulated above concerning the seat of origin of Immune body, the facts of the accumulation and retention of hen corpuscles in the liver and then phagocytosis there, and the fact of the great variation possible in the liver cell, I submit that the liver ought to be considered as a possible seat of origin of immune body. #26. To generalise, I would submit the possibility of the formation of antibodies being, in nature, the hypertrophy of a normal physiological process - a process which physiologically deals with overflow from the intestinal tract of material, toxic and non toxic, fluid and particulate, multiplying and non multiplying and which has escaped the process of intestinal digestion to which the bulk of absorbed material is subjected before absorption

Leading-edge slat optimization for maximum airfoil lift

A numerical procedure for determining the position (horizontal location, vertical location, and deflection) of a leading edge slat that maximizes the lift of multielement airfoils is presented. The structure of the flow field is calculated by iteratively coupling potential flow and boundary layer analysis. This aerodynamic calculation is combined with a constrained function minimization analysis to determine the position of a leading edge slat so that the suction peak on the nose of the main airfoil is minized. The slat position is constrained by the numerical procedure to ensure an attached boundary layer on the upper surface of the slat and to ensure negligible interaction between the slat wake and the boundary layer on the upper surface of the main airfoil. The highest angle attack at which this optimized slat position can maintain attached flow on the main airfoil defines the optimum slat position for maximum lift. The design method is demonstrated for an airfoil equipped with a leading-edge slat and a trailing edge, single-slotted flap. The theoretical results are compared with experimental data, obtained in the Ames 40 by 80 Foot Wind Tunnel, to verify experimentally the predicted slat position for maximum lift. The experimentally optimized slat position is in good agreement with the theoretical prediction, indicating that the theoretical procedure is a feasible design method

The LATDYN user's manual

The LATDYN User's Manual presents the capabilities and instructions for the LATDYN (Large Angle Transient DYNamics) computer program. The LATDYN program is a tool for analyzing the controlled or uncontrolled dynamic transient behavior of interconnected deformable multi-body systems which can undergo large angular motions of each body relative other bodies. The program accommodates large structural deformation as well as large rigid body rotations and is applicable, but not limited to, the following areas: (1) development of large flexible space structures; (2) slewing of large space structure components; (3) mechanisms with rigid or elastic components; and (4) robotic manipulations of beam members. Presently the program is limited to two dimensional problems, but in many cases, three dimensional problems can be exactly or approximately reduced to two dimensions. The program uses convected finite elements to affect the large angular motions involved in the analysis. General geometry is permitted. Detailed user input and output specifications are provided and discussed with example runstreams. To date, LATDYN has been configured for CDC/NOS and DEC VAX/VMS machines. All coding is in ANSII-77 FORTRAN. Detailed instructions regarding interfaces with particular computer operating systems and file structures are provided

Galliformes science and species extinctions: what we know and what we need to know

Extinciones de especies de Galliformes y conocimientos científicos: lo que sabemos y lo que necesitamos saber A principios de 2010, las 193 partes que habían firmado el Convenio sobre la Diversidad Biológica reconocieron que no habían cumplido el objetivo que ellas mismas habían fijado en 1992 de reducir de forma significativa las extinciones de especies en 2010. Al final del año establecieron un objetivo nuevo y más ambicioso que consistía en evitar las extinciones de especies en 2020. Lograr dicho objetivo requerirá una utilización mucho más eficiente de los recursos y la investigación tiene un papel fundamental en hacer que esto ocurra. Existen 290 especies de Galliformes, de las cuales el 26% se considera en peligro de extinción, en comparación con el 12% del total de las 10.000 especies de aves. Al mismo tiempo, hay numerosos estudios publicados sobre el grupo que abarcan décadas para algunas especies. Por consiguiente, es oportuno analizar si es posible aumentar la eficiencia y las repercusiones a escala mundial de la investigación sobre aves de caza, de forma que, con la planificación meticulosa que conlleva más orientación estratégica e intercambio de experiencias, los biólogos especializados en este tipo de aves puedan desempeñar una función destacada en la consecución del objetivo de 2020 para las especies aprobado por el Convenio sobre la Diversidad Biológica. Los ámbitos específicos que necesitan este planteamiento de intercambio de experiencias son la estimación de la población y la evaluación de las amenazas, el análisis de la explotación y la determinación de la base ecológica de las intervenciones que hayan obtenido buenos resultados

Weak Disorder in Fibonacci Sequences

We study how weak disorder affects the growth of the Fibonacci series. We introduce a family of stochastic sequences that grow by the normal Fibonacci recursion with probability 1-epsilon, but follow a different recursion rule with a small probability epsilon. We focus on the weak disorder limit and obtain the Lyapunov exponent, that characterizes the typical growth of the sequence elements, using perturbation theory. The limiting distribution for the ratio of consecutive sequence elements is obtained as well. A number of variations to the basic Fibonacci recursion including shift, doubling, and copying are considered.Comment: 4 pages, 2 figure

Late Quaternary vegetation history of North Stradbroke Island, Queensland, eastern Australia

Currently there is a paucity of records of late Quaternary palaeoenvironmental variability available from the subtropics of Australia. The three continuous palaeoecological records presented here, from North Stradbroke Island, subtropical Queensland, assist in bridging this large spatial gap in the current state of knowledge. The dominance of arboreal taxa in the pollen records throughout the past >40,000 years is in contrast with the majority of records from temperate Australia, and indicates a positive moisture balance for North Stradbroke Island. The charcoal records show considerable inter-site variability indicating the importance of local-scale events on individual records, and highlighting the caution that needs to be applied when interpreting a single site as a regional record. The variability in the burning regimes is interpreted as being influenced by both climatic and human factors. Despite this inter-site variability, broad environmental trends are identifiable, with changes in the three records comparable with the OZ-INTIMATE climate synthesis for the last 35,000 years. © 2013 Elsevier Ltd.Patrick T. Moss, John Tibby, Lynda Petherick, Hamish McGowan, Cameron Bar

Probing the Pulsar Wind Nebula of PSR B0355+54

We present XMM-Newton and Chandra X-ray observations of the middle-aged radio pulsar PSR B0355+54. Our X-ray observations reveal emission not only from the pulsar itself, but also from a compact diffuse component extending ~50'' in the opposite direction to the pulsar's proper motion. There is also evidence for the presence of fainter diffuse emission extending ~5' from the point source. The compact diffuse feature is well-fitted with a power-law, the index of which is consistent with the values found for other pulsar wind nebulae. The morphology of the diffuse component is similar to the ram-pressure confined pulsar wind nebulae detected for other sources. The X-ray emission from the pulsar itself is described well by a thermal plus power-law fit, with the thermal emission most likely originating in a hot polar cap.Comment: 9 pages (uses emulateapj.cls), 8 figures, 2 tables, accepted for publication in Ap

Optical Follow-up of New SMC Wing Be/X-ray Binaries

We investigate the optical counterparts of recently discovered Be/X-ray binaries in the Small Magellanic Cloud. In total four sources, SXP101, SXP700, SXP348 and SXP65.8 were detected during the Chandra Survey of the Wing of the SMC. SXP700 and SXP65.8 were previously unknown. Many optical ground based telescopes have been utilised in the optical follow-up, providing coverage in both the red and blue bands. This has led to the classification of all of the counterparts as Be stars and confirms that three lie within the Galactic spectral distribution of known Be/X-ray binaries. SXP101 lies outside this distribution becoming the latest spectral type known. Monitoring of the Halpha emission line suggests that all the sources bar SXP700 have highly variable circumstellar disks, possibly a result of their comparatively short orbital periods. Phase resolved X-ray spectroscopy has also been performed on SXP65.8, revealing that the emission is indeed harder during the passage of the X-ray beam through the line of sight.Comment: 9 pages, 9 figures, 2 tables, accepted for publication in MNRA

Limits on I-band microvariability of the Galactic Bulge Miras

We search for microvariability in a sample of 485 Mira variables with high quality I-band light curves from the second generation Optical Gravitational Lensing Experiment (OGLE-II). Rapid variations with amplitudes in the ~0.2-1.1 mag range lasting hours to days were discovered in Hipparcos data by de Laverny et al. (1998). Our search is primarily sensitive to events with time-scales of about 1 day, but retains a few percent efficiency (per object) for detecting unresolved microvariability events as short as 2 hours. We do not detect any candidate events. Assuming that the distribution of the event time profiles is identical to that from the Hipparcos light curves we derive the 95% confidence level upper limit of 0.038 per year per star for the rate of such events (1 per 26 years per average object of the ensemble). The high event rates of the order of 1 per year per star implied by the Hipparcos study in the H_P band are excluded with high confidence by the OGLE-II data in the I band. Our non-detection could still be explained by much redder spectral response of the I filter compared to the H_P band or by population differences between the bulge and the solar neighborhood. In any case, the OGLE-II I-band data provide the first limit on the rate of the postulated microvariability events in Mira stars and offer new quantitative constraints on their properties. Similar limits are obtained for other pulse shapes and a range of the assumed time-scales and size-frequency distributions.Comment: Accepted for publication in Ap