bluuebunny/crossref_metadata_2025 huggingface dataset:
Note on an Improved Short-Cut Method Jor Estimating Aircraft Direct Operating Costs
Authors: Robertson Frank
Published: August 2016

In the early stages of preliminary design, it is essential to have a method for the comparison of aircraft on an operating cost basis. The standard S.B.A.C. method is too lengthy and, in any case, demands a greater amount of data than is usually available in the early design stages.

The formula presented in this note is an extension to the ones presented by the author in the January 1955 and November 1956 Journals and is more accurate in that it provides for variation in aircraft first cost, type of power plant, speed and range.

It is submitted that the formula gives a reasonable first estimate, suitable for early design comparisons, and that the few parameters required are normally available at the earliest stage of the design.
Effects of Inlet Boundary Layer on Pressure Recovery, Energy Conversion and Losses in Conical Diffusers
Authors: Winternitz F. A. L. , Ramsay W. J.
Published: August 2016

A study has been made of the effect of inlet conditions on the performance of conical diffusers with 4:1 area ratio and 5 and 10 degrees total angle of expansion. The conditions at entry were varied by using different approach lengths of diffuser inlet diameter, and by means of projecting annular screens of woven wire cloth. With this new technique it was possible to vary the velocity distribution substantially within moderate settling lengths, and to produce velocity profiles with inflections. The suitability of the annular screen method of boundary layer generation for diffuser investigations was confirmed from the comparison with the approach length results.

Energy and pressure coefficients, as well as diffuser energy efficiency and the conversion efficiency, were found to depend on the diffuser angle β and the momentum thickness ratio at inlet θ/D0. The latter emerged as one of the chief parameters controlling diffuser performance. Variation in the inlet shape parameter H of the order of 20 per cent did not significantly affect the pressure recovery or the losses in the diffuser. For moderately thick boundary layers, θ/D0 X β<0·1, the diffuser angle could be eliminated as a parameter by plotting the pressure coefficient against θ/D0 X β. The Reynolds number based on diffuser inlet diameter was, for essentially incompressible flow, 2·5 X 105 in all tests.
Determination of Effective End Fixity of Columns with Unequal Rotational End Restraints by Means of Vibration Test Data
Authors: Bertram Klein
Published: August 2016

The determination of effective column end fixity by means of vibration testing has been established for the case when the rotational end restraints of the column are equal. It is the purpose of the present work to present solutions for the general case. The method of solution is straightforward. Results are listed in a convenient tabular array.
A Matrix Method for the Numerical Solution of Linear Differential Equations with Variable Coefficients
Authors: E. A. Winn
Published: August 2016

A method of solution of linear differential equations is derived which requires no special starting procedure, and which is, in principle at least, capable of extension to any order of accuracy. Further advantages of the method are that boundary conditions are easy to satisfy, and that the solution of families of equations differing only in the input function requires little extra computation. The method requires the reciprocation of a matrix of order equal to the number of points for which a solution is to be obtained, but this can be much simplified by suitably partitioning the matrix, and with most automatic high-speed computers the reciprocation of a matrix is in any case an easily programmed operation.
Optimum Conditions for the Operation of Airline Aircraft
Authors: Stephenson J. M.
Published: August 2016

In A. H. Stratford's interesting note in the August Journal, he assumes that an airline is presented with an aircraft of given performance, and must decide what is the best range for it to fly. Surely the practical case is the exact opposite: that an operator wishes to carry passengers or freight between two given points, and must choose between perhaps three or four available types of aircraft. Moreover, it is up to the operator to tell the manufacturers which feature he wants improved (e.g. fuel consumption, take-off distance, and so on), when he is ready to order replacements.

Secondly, Mr. Stratford wishes to replace the usual concept of direct operating cost per payload ton mile by that of per cent, profit, as a measure of the efficiency of operation over a certain route. While this may be a more realistic approach to the problem of a private airline company, operating over a single route, its merit is not so obvious for the large national or subsidised airlines, which are often required to fly unprofitable routes.
Aviation and the Development of Remote Areas
Authors:   H.R.H. The Duke of Edinburgh, K.G., K.T.
Published: August 2016

It is a very great honour indeed to find myself addressing the Royal Aeronautical Society. If, as I am often told, “a little learning is a dangerous thing” then you are in for a very dangerous address. For much as I would like to say that I know nothing about aviation it would not be altogether true. My knowledge is of the picked-up rather than the learned variety. During the war I was either at the receiving end of enemy aviation or under a friendly and comforting umbrella, which counts as passive experience. I started flying as a passenger in about 1935, and in common with many others 1 have put up with all the frustrations and delays of airline travel, particularly getting to and from the airfields—this I put down to semi–active experience! The active part of my experience began two short years ago when I started to learn to fly.

From this you will gather that any views I express this evening must be treated with caution if nothing else.
The Aerodynamic and Aeroelastic Characteristics of the Crescent Wing
Authors: Lee G. H.
Published: August 2016

It would be possible to write a paper conforming, literally, to the above title in very few words by simply describing the behaviour of the crescent wing in various circumstances. Such treatment, however, would avoid what is really the prime question of all, namely, why is the crescent wing used? What is the attraction of this layout? The answer to that question is performance. One essential characteristic of the crescent wing is thus its performance characteristic.

Therefore, in this paper, the matter will be introduced from a performance angle and an attempt will be made to show, in general terms, why there should be a performance gain from the crescent layout. Having established the case, the aerodynamic and aeroelastic characteristics will be considered in some detail so that, with these properties explained, the way will be clear to consider a performance comparison in greater detail and thus gain a fuller appreciation of the situation.
Flow Studies of the Leading Edge Stall on a Swept-Back Wing at High Incidence
Authors: Black Joseph
Published: August 2016

The flow separation on a swept-back wing with 44 degrees leading edge sweep at 18 degrees incidence has been investigated by means of detailed pressure distribution measurements over the leading edge, boundary layer flow determination with liquid film technique, and yawmeter traverses. A wool-tuft grid was also used, and a spin detector was developed to search for regions of vorticity. These tests established that the flow separates on the leading edge; over the inboard sections it re-attaches behind a “ short” separation bubble, while outboard it only re-attaches near the trailing edge, thus forming a “ long ” separation bubble, or else fails to attach. The separated flow in what has been commonly called the tip stall does in fact take the form of a “ ram's horn “ vortex with the origin, or “ tip,” located at the junction of the two bubbles on the leading edge. The vortex lies outwards across the wing surface at approximately 20 to 25 degrees to the line-of-flight before curving aft to be shed into the wake, where it extends almost from mid semi-span to the wing tip. This vortex induces considerable changes in flow direction, both on and over the wing, and also in the wake. Thus in the wake a maximum downwash of 23 degrees is induced aft of the mid semi-span, and there is an upwash of 17 degrees at the outer edge of the vortex, almost aft of the tip. A good correlation between yawmeter results and the boundary layer flow direction indications from the liquid film technique was obtained.
A New Concept in the Design of Jet Engine Mufflers and Test Cells
Authors: Richards E. J. , Evans D. J.
Published: August 2016

A new concept is put forward which should help materially in the design of engine test cells and ground mufflers. It is suggested that a relatively small spreader can be added behind a jet nozzle which changes, the shape of the jet from circular to a long annular slot. The frequency rise which may be obtained in this way is used to reduce low frequency noise, possibly at the expense of more easily attenuated high frequency noise. As a modest example, tests are described on one particular version which gives an attenuation in the most important low frequency range of nearly 20 decibels. It is shown that the back pressure on the engine is negligible even with a cooling flow equal to the engine mass flow. Other applications are discussed and tested, while suggestions for full scale installations are made.
A Tension Field Calculator
Authors: Noble K. G. F.
Published: August 2016

The calculator is a device in slide rule form for assisting in the design and stressing of flat rectangular panels in shear.

In the Incomplete Tension Field theory, the ratio q/qb becomes an important factor, where

q applied shear stress (lb./in.2)

qb shear stress at which panel first buckles (lb./in.2).

This ratio is normally evaluated by use of the formula

qb = KE(t/b)2

where E Young's modulus (lb./in.2)

t thickness of panel (in.)

a length of longer side of panel (in.)

b length of shorter side of panel (in.)

and K depends on the value of b/a and the edge conditions, and is normally obtained from R.Ae.S. Data Sheet 02.03.01.

This method becomes laborious when dealing with large numbers of panels.

By the use of the Calculator, q/qb may be found quickly, with no unnecessary paper work.
The Skid-Resisting Properties of Wet Surfaces at High Speeds: Exploratory Measurements with a Small Braking Force Trailer
Authors: Giles C. G. , Lander F. T. W.
Published: August 2016

The effectiveness of any braking system is ultimately limited by the point at which the wheels lock and slide over the surface on which the stop is being made. When surfaces are clean and dry the adhesion with a rubber tyre is high enough to meet most requirements of braking without risk of skidding. In wet, or in icy conditions, however, adhesion may be reduced to such an extent that, even with efficient brakes, stopping distances are greatly increased and dangerous conditions can arise. Under wet conditions there are special difficulties. Different surfaces may have very different skid-resisting properties and, in addition, when surfaces are wet, the adhesion with a tyre depends on speed, generally diminishing as speed is raised.
A Simple Method of Constructing Duct Models for the Electrolytic Tank
Authors: Norbury J. F. , Platt A.
Published: August 2016

A problem which occurs frequently is that of choosing a suitable shape for a duct, such as a wind tunnel contraction or an air intake. Basically similar problems, involving potential flow fields, occur in other branches of engineering, particularly in electrical engineering, and the electrolytic tank is now established as a tool which may usefully be employed in their investigation. The use of the simple shallow tank is limited to those fields which can be treated as two-dimensional or axisymmetric, but many problems fall within these categories.

In forming a duct model for the electrolytic tank the walls of the duct are represented by insulating surfaces, and electrodes are positioned to represent two suitable velocity potential surfaces up- and down-stream of the duct. To represent a sector of an axi-symmetric duct the base of the tank must be inclined at 3°-5° to the horizontal and the water line on the tank base then represents the axis of symmetry.
Torsional Vibrations of a Multi-Rotor System Having a Non-Linear Flexible Coupling
Authors: Mahalingam S.
Published: August 2016

The free and forced vibrations of a multi-rotor system where one section of the shaft has a nonlinear elastic characteristic are considered in this paper. For any frequency of steady vibration the system is reduced to an equivalent rotor at either end of the nonlinear section. The vibrations at all points are assumed to be one-term approximate solutions and the amplitudes of steady forced vibration are determined by a method outlined by the author in an earlier paper.
The Derivation and Estimation of Aerodynamic Loads for Stressing Purposes
Authors: Lambert D. J.
Published: August 2016

The rational estimation and derivation of aerodynamic loading data is becoming of rapidly increasing importance in the design of modern aircraft. The great advances made in aircraft performance during the 1939-45 War, together with the generally detrimental effect of compressibility upon stressing loads, have combined to make the task of the structural designer much more difficult. A few years ago, the loads resulting from the often arbitrary stressing cases of A.P.970 (Ministry of Supply Air Publication 970, Design Requirements for Aeroplanes for the Royal Air Force and Royal Navy) were of relatively minor significance and furthermore, any inaccuracies in their estimation and derivation were covered almost always by the ultimate factor if the estimate were on the low side, while if the loads were conservative, the weight penalties and structural difficulties involved were small.
Nose-Wheel Steering Systems
Authors: Conway H. G.
Published: August 2016

These notes are intended to summarise for the benefit of aeronautical students the basic requirements of nose-wheel steering hydraulic systems. The various factors which have to be considered are listed and representative solutions given.
Some Problems in Aerodynamics and Their Solution by Electrical Analogy
Authors: Küchemann D. , Redshaw S. C.
Published: August 2016

Some purely aerodynamical phenomena, which might profitably be investigated by means of electrical analogue computors, are described. No attempt has been made to furnish a complete catalogue of problems but rather to present current issues, the solution of which would aid the development of practical aerodynamics.

Consideration has only been given to those questions which can be solved more suitably by an analogue computor rather than by a digital machine, although the feasibility of partially solving certain of them by the use of an analogue computor, and completing the work with a digital machine, is mentioned.

In scope, the survey includes two and three dimensional aerofoils as well as interference and a number of special problems.

The relative merits of the various forms of analogue computors are not extensively discussed.
Fatigue Aspects of Structural Design
Authors: Fisher W. A. P.
Published: August 2016

The problems associated with the fatigue life of aeroplane structures have been so thoroughly discussed by experts of international repute that it is with some trepidation that the present speaker ventures into this difficult and controversial field. However, the need for more experimental fatigue data on actual structural components (as distinct from idealised test specimens) is undeniable; further, it is hoped that the present paper may stimulate discussion. Opinions expressed in this paper are the author's personal views, and do not necessarily reflect the policy of the Ministry of Supply.

A comprehensive bibliography on this subject has been given recently by Lundberg in the 18th Wright Brothers’ Lecture.
The Size of Aerofoil Models for Quantitative Hydraulic Analogy Research
Authors: Bryant R. A. A.
Published: August 2016

In a recent article Lundberg has made reference to use of the “ Hydraulic Analogy ” for quantitative investigation of gas dynamics phenomena. This is quite feasible provided that the basic analogy and its limitations are properly understood. In fact, considerable progress has already been made and it has been proved possible to utilise the analogy for both supersonic and transonic research.

A study of the mathematical analogy indicates that the strongest physical analogy between a two-dimensional (inviscid) gas flow and a three-dimensional (viscous) water flow exists for the transonic case when the water depth is approximately one quarter inch and the model is towed. Only thin profiles with small incidence can be sensibly investigated. Under such conditions the analogous water flow may be considered as a distorted dissimilar model of a corresponding prototype gas flow.
Fins
Authors: Wolkovitch J.
Published: August 2016

Judging by the number of present-day aircraft which have suffered changes of fin shape, it is clear that there is still some difficulty in estimating the size and shape of fin required on a new project. In this paper some of the principles on which fin design is based will be explained, and some of the difficulties involved described.

It is necessary to have some sort of fin to provide weathercock, or directional, stability. This is illustrated in Fig. 1. This shows the balance of yawing moments, due to sideslipping. In general, the side force acting on the fuselage, represented by the black arrow, has its c.p. ahead of the e.g. of the aircraft, and hence it produces a destabilising moment about the e.g. Sufficient fin area must be provided for the yawing moment due to the fin side force, represented by the white arrow, to at least equal the destabilising fuselage moment. Otherwise, when disturbed laterally due to, say, a gust, the aeroplane will tend to swing still further out of wind, making it difficult to fly accurately. The minimum permissible fin area can, in fact, be fixed simply by this requirement for weathercock stability.
A Review of Some Combustion Problems Associated with the Aero Gas Turbine
Authors: Clarke J. S.
Published: August 2016

The 23rd Main Lecture to be given before a Branch of the Society was held under the auspices of the Merthyr Tydfil Branch on 10th November 1955. The Lecture, entitled “A Review of Some Combustion Problems Associated with the Aero Gas Turbine,” was given by Dr. J. S. Clarke, O.B.E., M.I.Mech.E., F.R.Ae.S. Mr. C. S. Gardner, Past President of the Merthyr Tydfil Branch, opened the proceedings by welcoming the guests. He was deputising for Mr. W. R. Morgan, the Branch President, who had unfortunately had to go into a nursing home for treatment for an old war injury. He apologised also for the absence of Mr. McGibbon who arrived back from America only that day and was unable to be present. He then introduced Mr. N. E. Rowe, President of the Royal Aeronautical Society, whom they were very honoured indeed to have with them. When they thought of the journeyings that his presence involved he thought they should be all the more grateful that he could come and support them in their Branch. He would ask Mr. Rowe to take the Chair.
End-Fitting Effects in Strut Tests
Authors: Chilver A. H.
Published: August 2016

In a recent study of the buckling of pin-ended struts of a certain light-alloy material the author found it necessary to use ball-end fittings which supported rigidly an appreciable length of the strut. For some of the struts—having slenderness ratios of the order of 20—the unsupported length was only about a quarter of the overall length between pinned-ends, (Fig. 1). The effect of rigid end-fittings can easily be taken into account in calculating the elastic buckling load of this system. The author expected to find this end effect important for shorter struts; however, this is not the case. In fact, buckling of the strut is governed largely by the flexibility of the unsupported length, and even large end fittings may not affect appreciably the buckling load.
The Twist Due To Bending Moment in Cantilevers Curved in flan
Authors: Johnson W.
Published: August 2016

The twist that arises from bending stresses in straight cantilevers of thin-walled section asymmetrical about any vertical plane, is well known and eventually leads to the concept of a shear centre. If an analysis is made along the same lines as that used for investigating straight beams, of cantilevers curved in plan, it is found that the bending moments transmitted are again responsible for shear stresses in the flanges of the beam and cause twisting.

The following analyses refer, principally, to cases in which the cantilever carries a concentrated load at its end and are confined to the relatively simple forms of the channel and I-section. Each cantilever is perfectly built-in at one end and, for simplicity, it is considered that the web of a section offers no resistance to bending and that the beams are of constant curvature in plan.
Natural Frequencies of Constant Thickness Cantilever Triangular Plates oj Arbitrary Plan Form
Authors: Klein Bertram
Published: August 2016

Simple Formulae are presented for the first three bending-type and the first torsion-type natural frequencies of any constant thickness cantilever triangular plate. The formulae are derived by a semi-empirical method. Comparison of calculated frequencies with test values indicates agreement within a few per cent. for a variety of plate plan forms.
Steel Tubes, Tube Manipulation and Tubular Structures for Aircraft
Authors: Hackett W. W.
Published: August 2016

It is now more than ten years since, in conjunction with my brother, I gave a lecture to your Society in London on “Steel Tubes, Tube Manipulation and Tubular Structures for Aircraft.” Since that time great progress has been made both in the production and manipulation of steel tubing. Things which were thought ten years ago to be impossible are now being done and it is, therefore, desirable that the paper should be brought up-to-date.
The Streamline Aeroplane
Authors: Melvill Jones B.
Published: August 2016

Ever since I first began to study Aeronautics I have been annoyed by the vast gap which has existed between the power actually expended on mechanical flight and the power ultimately necessary for flight in a correctly shaped aeroplane. Every year, during my summer holiday, this annoyance is aggravated by contemplating the effortless flight of the sea birds and the correlated phenomenon of the beauty and grace of their forms.
Engineering Aspects of Commercial High Altitude Flying
Authors: Younger John E.
Published: August 2016

This paper presents the twenty or more principal problems encountered in the designing of aeroplanes for passenger service at altitudes of about 20,000 to 30,000 feet, together with a discussion of the recent attempts made in the United States to solve these problems. Particular attention is given to the design features of pressure cabins for maintaining low altitude air pressure at high altitudes.
Methods of Solving Special Geometric Problems in Connection with Aircraft Design
Authors: Chaplin H. E.
Published: August 2016

In many branches of engineering, especially the aircraft industry, numerous geometric problems arise which present considerable difficulty to draughtsmen and designers. The object of this paper is to present methods which the writer has developed which enable any problem of the type under consideration to be rapidly solved. The majority of these problems arise in cases where, although sufficient data is provided to enable ordinary three view drawings of a particular part or assembly of parts to be made, angles and lengths have to be found which cannot be directly obtained from this three view drawing.
Ground Transport for an Air Organisation
Authors: Allen R. E. H.
Published: August 2016

Probably few realise that a self–contained organisation for maintaining an air fleet would need many more different types of ground vehicles than aircraft. This is true in the case of the Royal Air Force even if all vehicles of a purely military nature are excluded. It is highly probable that a civilian air organisation of similar magnitude would have fewer types of aircraft, but if it were to be self–contained and operate in different parts of the globe, it could not do with many less types of ground vehicles than the R.A.F. finds necessary.

Obviously this depends on the interpretation of the term “self–contained.” Most of the small aerial transport companies have their own ground transport organisations, but they are far from being self–contained in the sense in which the author wishes to use the term to–night. We would all like to see a vast civilian air organisation operating in and between all the different units which comprise the British Empire. Nothing would do more to knit us and the Dominions and Colonies into one impregnable whole.
Man and the Machine
Authors: Flack Martin
Published: August 2016

What may be termed broadly the medical aspects of flying are far more wide–reaching than is generally supposed, especially since such a term embraces both the physiological and psychological aspects of the subject. All the while, therefore, that man acts as the controlling and co–ordinating mechanism of the machine, the study of man in relation to his machine must occupy an important place in the progress of aviation. It is because this aspect of the subject has tended to be somewhat overlooked that I venture to address this Society again to–night.

In the first place I wish to consider what happens when a man learns to fly. As the result of information gleaned by his various senses he is taught, according to his aptitude, to perform or to try to perform certain arm and leg movements which will control the machine safely while it is in the air. To do this, however, in addition to perceiving, he must in certain circumstances display judgment before he acts, although, as he becomes more experienced in flying, he will automatically perform certain movements in response to certain sensations.
Aeronautics
Authors: Guidoni A.
Published: August 2016

Since the vaiious nations definitely set out upon the course of aeronautical armaments, the problem of the organisation of this new service has arisen, and appears to present serious difficulties if it should be necessary to effect periodical changes and modifications or at least substitutions in personnel.

This uncertainty is due partly to the fact that quite new questions are being dealt with; partly to the erroneous process of enforcing upon the new fighting service the rules of the older ones—the army and navy; and in a larger measure to the practical difficulties which have to be faced at every turn in passing from the theoretical field to the actual.

In the following pages an attempt is made to present the chief problems which arise in the aeronautical field, so as to form an idea for their solution, adducing opinions frequently diverse and antagonistic which the experts maintain in their respective arguments.
Extracts from the Scientific and Technical Press
Authors: R.T.P.
Published: August 2016

Physical–chemical study of light fuels and of lubricants in Aeronautics. (M. Moutte, La Technique Aeronautique, Sept.–Oct., 1926, pp. 279-281 and 305-319) (8.51/5096 France)

Systematic tests of fuels in an engine on the test bench were commenced in 1917, in conjunction with a systematic determination of physical properties, and as far as possible of chemical composition. It was found that homogeneity, volatility and high latent heat of evaporisation were the most desirable qualities. In agreement with Ricardo, the aromatic compounds of hydrogen are found to be the least amenable to propagation of explosion, then the saturated cyclic compounds, and lastly the saturated acyclic compounds. In identifying fuels use is made of characteristic curves of distillation:—

Temperature—Volume Distilled, Density;—Volume Distilled.

Temperature—Density, Temperature—Solubility.

Temperature of distillation plotted against critical temperature of solubility in aniline gives highly characteristic differences, and is considered a fundamental method. Optical methods are also used for approximate quantitative determination. The formation of clouds of condensed drops affords another method of determination. The mechanical conditions were also examined:—Variation of inlet pressure, condensation, centrifugal separation.
Airships
Authors: Wyn Evans H. B.
Published: August 2016

Not to go too far back in years, and to relate a few facts within the lifetime of most of you present to-night, I may commence by saying that it was in 1909 that Admiral Lord Fisher instructed Admiral Bacon to proceed with the design and construction of a rigid airship, attention having been called to the success attending Count Zeppelin's efforts and to the fact that we could not realise the dangers to which we might be exposed until we possessed airships of our own.

Admiral Bacon got into touch with Messrs. Vickers' experts, and Naval Airship No. 1, nicknamed the “ Mayfly,” was built at Barrow. Messrs. Vickers deserve all credit for their pioneer work on airship design and construction in this country, and it was only very bad luck that prevented their building the bigger ships.
Fog
Authors: Entwistle F.
Published: August 2016

Among the various applications of meteorology to the practical requirements of everyday life, the observation of fog, as a meteorological element, has. been associated primarily, in the past, with locomotion on land and with navigation on the sea. The first scale of fog intensity used by meteorological observers in this country was, in fact, based on the effect of different degrees of atmospheric obscurity on navigation. The scale was drawn up in 1903 as the result of an investigation into the conditions of formation of London fogs, and subsequently modified by the Meteorological Office, in conjunction with the Admiralty and Trinity House (see Table I.). It included five specifications of fog intensity ranging from a clear atmosphere free from fog or mist, represented by “ of,” to a thick fog, denoted by “ sf.”

Within the last twelve years, while the importance of fog as an obstruction to road and rail transport and to shipping has in no way diminished, the reporting and forecasting of fog has assumed a new significance in relation to air navigation.
Valve Steels
Authors: Henshaw P. B.
Published: August 2016

In introducing the subject of valve steels to this Society I do so, not because of any special knowledge which I possess, but on account of the general interest which is being taken in the subject at the present time. It is quite evident that the valve steels which have been regularly used are not satisfactorily meeting all the present conditions, and therefore advances will have to be made, especially as much greater engine efficiencies are being demanded. Presumably the valve has to withstand much severer conditions than formerly. In many cases the result, as far as the valve is concerned, means a higher working temperature, which in turn affects many other properties of the steel such as scaling, the tendency to air-harden, etc.
An Interview with Jim Eisenreich
Authors: Fuerst Mark L.
Published: August 2016

Seventeen years after professional baseball player Jim Eisenreich first developed symptoms of Tourette syndrome (TS), the correct diagnosis was finally made.

At age 6, his rapid eye blinking led to a diagnosis of hyperactivity. “I was told I would grow out of it,” says the 39-year-old Eisenreich, who may have played his last game as a Los Angeles Dodger. “I knew I was different even then.”

In the early 1980s, Eisenreich's condition first became public. Since then, his achievements as a professional athlete have made him a role model for other TS patients.

Sports were always a haven for him as he grew up. “I found peace, comfort, and security in sports. Whatever the season, I played the sport—football, baseball, hockey,” says Eisenreich. “Socially, I didn't go to the movies or go out much with girls.”

After 2 years in the minor leagues, he was called up by the Minnesota Twins in 1982 as an outfielder. During the season, a TS specialist recognized his grunting and sniffling as signs of the disease. “I had no idea what the specialist was talking about, and the Twins doctors dismissed it because I didn't have copralalia,” he says. The Twins team physician (an internist) prescribed a sedative. Then Eisenreich tried Inderal, which caused hyperventilation, and Catapres, which caused depression.
Sleep Patterns in Patients with OCD
Authors: Okasha A. , El Sayed M. , Asaad T. , El Dawla A. Self , Okasha T.
Published: August 2016

Objectives:

(1) To determine whether there are sleep variables specific for obsessive-compulsive disorder (OCD) that are identifiable on polysomnographic findings; (2) to determine the possible relationship of OCD to other psychopathological disorders, with special emphasis on major depressive disorder (MDD).

Methods:

Eighteen patients suffering from OCD (five of whom had a comorbid depressive disorder) were assessed by means of a standardized sleep questionnaire, the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) for the assessment of severity of obsessive-compulsive symptoms, and overnight polysomnography. Results were compared with those from a control group of 18 age- and sex-matched controls with no history of psychiatric disorders.

Results:

We found a significant decrease in sleep efficiency index (SEI), REM percent, REM latency, and slow wave sleep latency among OCD patients, compared with controls. The presence of comorbid major depression had no effect on the severity of OCD and had no significant effect on the sleep measures.

Conclusions:

Sleep changes recorded polysomnographically in patients with OCD can be primary in origin and are independent of an associated major depressive disorder.
Obsessions, Compulsions, Clozapine, and Risperidone
Authors: Baker Robert W. , Bermanzdhn Paul D. , Wirshing Donna Ames , Dhengappa K. N. Roy
Published: August 2016

In the past decade, clozapine, risperidone, and olanzapine were marketed for the first time in the United States, and other new antipsychotic drugs are expected to follow soon. Also within the past decade, the efficacy of serotonin-reuptake inhibitors (SRIs) has been demonstrated in patients with obsessive-compulsive disorder (OCD) and the serotonin hypothesis of OCD has been articulated clearly.
Obsessions and Delusions: Separate and Distinct, or Overlapping?
Authors: Bermanzohn Paul C. , Porto Linda , Arlow Phyllis B. , Axelrod Sylvia , Stronger Roslyn , Martino-beyer Jeannette , Pollack Simcha , Siris Samuel G.
Published: August 2016

The convergence of obsessive and schizophrenic symptoms, particularly the blending of obsessional and delusional features into complex symptoms, calls for a clarification of the relationship between obsessions and delusions, which are usually thought of as separate and distinct, even opposite entities. This brief review is a preliminary attempt to assess some of the difficult issues raised by these phenomena.

We evaluate obsessions and delusions, and how they may overlap. A patient's degree of insight has been deemed a determining factor in distinguishing between these primary symptoms. However, our review of the literature shows that a definite distinction between obsessions and delusions cannot be made solely on the basis of insight.
Diagnosis and Epidemiology of Parkinson's Disease
Authors: Simuni Tanya , Stern Matthew B.
Published: August 2016

Parkinson's disease (PD) is one of the most common neurodegenerative diseases. The last 5 years have been marked by rapid developments in understanding the pathophysiology of PD as well as by the introduction of a number of new drugs for symptomatic treatment of the disease. On the other hand, the diagnosis of PD is still made purely on clinical grounds. Due to continuing advances in therapy, it is increasingly important to recognize PD in its earliest stages and to distinguish it from other causes of parkinsonism, for which prognosis and response to treatment differ. This article reviews the epidemiology of PD and then elaborates on the diagnosis and differential diagnosis.
COMT Inhibitors: Novel Treatments for Parkinson's Disease
Authors: Adler Charles H.
Published: August 2016

Catechol-O-methyltransferase (COMT) inhibitors are a new class of medication being developed for the treatment of Parkinson's disease (PD). The enzyme COMT metabolizes levodopa and dopamine, both peripherally and centrally. Coadministration of a COMT inhibitor with levodopa creates an increase in peripheral and central levodopa bioavailability, as well as higher central dopamine concentrations. Because these actions improve the duration of response to levodopa, the COMT inhibitors should prove to be useful adjunctive therapies in PD patients.
The Spectrum Model: A More Coherent Approach to the Complexity of Psychiatric Symptomatology
Authors: Frank Ellen , Cassano Giovanni B. , Shear M. Katherine , Rotondo Alessandro , Dell'Osso Liliana , Mauri Mauro , Maser Jack , Grochocinski Victoria
Published: August 2016

The current tools used to define and diagnose mental disorders, including the Diagnostic and Statistical Manual of Mental Disorders and the International Classification of Diseases, have added specificity to the psychiatric nomenclature. However, their stereotypic rigidity in classification has resulted in the failure to identify the full range of potentially debilitating psychiatric symptoms with which patients may present. A spectrum model of psychopathology is more adept at recognizing the subclinical or threshold symptomatology that may occur concomitantly with core psychiatric disorders. The authors discuss the development of a spectrum approach to the diagnosis of mental disorders, which offers the potential to improve treatment selection and therapeutic outcomes.
Trichotillomania in Children and Adolescents
Authors: Reeve Elizabeth A. , Keuthen Nancy J.
Published: August 2016

Trichotillomania (TTM), or hair pulling, in children and adolescents is a heterogeneous disorder requiring a sophisticated approach to each patient. Hair pulling in a young, preschool child may have a different etiology and prognosis than hair pulling in an adolescent. Treatment providers must have a clear understanding of an individual's hair-pulling history, family interactions, and comorbid psychiatric diagnoses. Behavioral strategies are the primary treatment for most children and adolescents, although there may be indications for pharmacotherapy in some individuals. While research in adult TTM has been increasing in recent years, fewer studies have investigated childhood hair pulling. This article will discuss aspects of TTM unique to children and adolescents and will provide a clinical description of childhood hair pullers and treatment strategies.
OC Spectrum Disorders: The Impulsive and Schizo-Obsessive Clusters
Authors: Hollander Eric , Rosen Jennifer ,   IOCDC OC Spectrum Work Group
Published: August 2016

Two symptom clusters within the obsessive-compulsive (OC) spectrum—the impulsive cluster and the schizo-obsessive cluster—are discussed in this paper. Disorders characterized by impulsivity include disorders of impulse control (eg, intermittent explosive disorder, pyromania, kleptomania, pathologic gambling, trichotillomania); paraphilias, sexual impulsions, and sexual addictions; and impulsive aggression personality disorders (eg, borderline, antisocial, histrionic, and narcissistic personality disorders). The schizo-obsessive cluster includes comorbid symptoms of obsessive-compulsive disorder (OCD) and schizophrenia. Both clusters of disorders have a substantial impact on individuals and society. This article examines the overlap of symptoms between OCD and OC spectrum disorders, along with possible treatment options. Studies on the effectiveness of serotonin reuptake inhibitors in treating pathologic gambling, compulsive buying, and comorbid OCD and schizophrenia are presented. The need for additional large scale, adequately-controlled studies is discussed.
Circadian Rhythms in Medicine
Authors: Smolensky Michael H.
Published: August 2016

Circadian (24-hour) rhythms are important to the practice of medicine. The phasing and amplitude of key physiologic and biochemical circadian rhythms contribute to predict in-time patterns in the manifestation and exacerbation of most medical conditions. Moreover, body rhythms can significantly affect responses of patients to diagnostic tests and medications. Rhythmicity in the pathophysiology of medical conditions is the rationale for chronotherapeutics—the purposeful variance of the concentration of medicines in synchrony with biological rhythm-determinants of disease activity—to optimize treatment outcomes. This article discusses the concept of biological time structure and its relevance to the practice of medicine, with a focus on neurologic issues.
Medically Unexplained Physical Symptoms: Toward an Alternative Paradigm for Diagnosis and Treatment
Authors: Ballas Christos A. , Staab Jeffrey P.
Published: August 2016

The treatment of patients with unexplained medical symptoms is difficult because there is neither a clear etiology for the symptoms, nor a useful paradigm with which to understand and treat them. Patients with such symptoms are often referred to psychiatry with vague diagnoses of “somatization” or “hypochondriasis.” Rather than considering somatoform diagnoses based on the number or diversity of physical symptoms, evolving research suggests an emphasis on the type of physical symptom as an indicator of Axis I pathology. This article links specific symptomatic complaints, such as chronic pain, chest pain, and dizziness, to the respective Axis I disorders associated with them, such as depression, panic disorder, and anxiety disorders.
Understanding the Delay Before Epilepsy Surgery: Who Develops Intractable Focal Epilepsy and When?
Authors: Berg Anne T.
Published: August 2016

Intractable temporal lobe epilepsy that is surgically treated in adulthood is a disorder whose onset frequently occurs during childhood and early adolescence. The average duration of epilepsy prior to surgery is on the order of 20 years. The long delay between onset and surgery has at least two components: time from onset to intractability and time from evidence of intractability to surgery. The first interval is prolonged >10 years especially if the onset is during childhood. This suggests a complex natural history that we have not fully appreciated as well as a potential window of opportunity for early secondary intervention. The second interval is also prolonged, especially if onset was during childhood. Reasons for this are not fully clear but may include a reluctance to consider surgery and perhaps difficulty deciding whether seizures are sufficiently intractable to warrant surgery especially after what may have been a relatively benign initial course. Factors involved in the second delay need to be better understood so that surgical interventions can be appropriately targeted early rather than late, thereby reducing serious social, psychological, and educational consequences associated with uncontrolled seizures.
Is Obsessive-Compulsive Disorder Caused by a Second-Messenger Imbalance?
Authors: Marazziti Donatella , Perez Jorge , Cassano Giovanni B.
Published: August 2016

Although the precise etiologic nature of obsessive-compulsive disorder (OCD), one of the most common psychiatric conditions, is unknown, several findings indicate involvement of the serotonin (5-HT) transporter. Apart from the specific effects of selective 5-HT reuptake inhibitors, other studies show decreased functionality of the platelet 5-HT transporter in OCD. In this report, the authors combine data from two independent studies of patients with OCD, showing both an increased activity of protein kinase type C (PKC) and a decreased activity of protein kinase type A (PKA). The authors propose a unifying hypothesis that OCD might be determined by an imbalance between PKC and PKA, with a prevalence of the former and, more generally, of the phosphoinositide over the cyclic adenosine monophosphate (cAMP) pathway. Should this hypothesis prove correct, the path would be open for new therapeutic interventions in the treatment of OCD.
Using Neuroimaging to Understand Alcohol's Brain Effects
Authors: George Mark S. , Teneback Charlotte C. , Bloomer Courtnay W. , Horner Michael D. , Anton Raymond F.
Published: August 2016

Some of the profound effects alcohol has on the brain were discovered years ago through pathological studies at autopsy. However, the recent development of new tools for structural and functional brain imaging has enabled researchers to expand upon this earlier knowledge. For example, some imaging studies have revealed that chronic alcohol consumption causes cortical loss, some of which is reversible with abstinence. Other studies have found that alcohol acts as a global central nervous system depressant, with chronic use resulting in reduced activity that can take a month or more to recover. Finally, imaging tools are also beginning to shed light on which brain regions are active when an alcoholic has the urge to drink.
Phenotypic Variability in Obsessive-Compulsive Disorder and Its Relationship to Familial Risk
Authors: Pauls David L.
Published: August 2016

Twin and family studies of obsessive-compulsive disorder (OCD) have gleaned important data regarding the influence of genetic factors in the development of this disorder. These studies have shown that understanding the importance of genetic factors in OCD is largely dependent upon how the phenotype is classified. The last decade of research has found that substantial variability of symptomatology exists across individuals diagnosed with OCD. Considering this, a number of analyses have been conducted to determine if possible subtypes of OCD exist, including analysis of age of onset, cluster analysis, factor analysis, and segregation analysis. These methodologies, and possibly others, could aid in identifying the genes involved in the development of OCD.
Catatonia in Affective Disorder: New Findings and a Review of the Literature
Authors: Krüger Stephanie , Bräunig Peter
Published: August 2016

The historical development of the concept of catatonia in affective disorders and contemporary papers on this topic are reviewed. In addition, data from a current study on the frequency of catatonia in mixed mania are reported. Differences between catatonic and noncatatonic patients with mixed mania are presented and their relevance to clinical practice is discussed.
Is Lorazepam a Treatment for Neuroleptic Malignant Syndrome?
Authors: Francis Andrew , Chandragiri Sanjay , Rizvi Syed , Koch Monika , Petrides Georgios
Published: August 2016

The authors assessed the ability of lorazepam and other benzodiazepines to affect the course of neuroleptic malignant syndrome (NMS). Records of inpatients who met both stringent research criteria and criteria under the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, (DSM-IV) (n=11) or DSM-IV criteria alone (n=5)for NMS were identified. All received lorazepam or related benzodiazepines within 24 hours of NMS onset or hospital admission. The records were reviewed for resolution of clinical signs NMS. Rigidity and fever abated within 24—48 hours, while secondary features of NMS were relieved within 64 hours. These results compared favorably with prior reports of 5-day to 10-day recovery periods. Benzodiazepine administration appeared to be well tolerated. Lorazepam and related benzodiazepines may reduce recovery time in NMS.