Profitable Areas Research Articles

From Hacienda to Family Farm: Changes in Environment and Society in Pimampiro, Ecuador

Environmental change is often a consequence of modifications in local and national society as much as it is of the particular nature of different ecological situations. This assertion is demonstrated to be true in one part of the Ecuadorian Andes in two historical periods: from 1900 until 1960 and from 1960 to 1983. The analysis of the earlier period is based on contemporary accounts and historical analysis. Land use changes are shown to have reflected the evolving attitudes of the landowning class to farming. On the basis of fieldwork on two occasions in the past 25 years, it is demonstrated that the extension of ownership of middle-sized properties to a new social group has created a more profitable area of farming near to the town, while the distant hillsides become less used.

Research Planning and Evaluation in the U.S. Forest Service

As public agency budgets have tightened in recent years, research policymakers and administrators have recognized the need to improve the planning and evaluation of research projects and programs. This article describes the current planning and evaluation process in U.S. Forest Service research. Options for improving this process are then discussed, including strengthening medium-range research planning, introducing formal preevaluation, monitoring research progress more closely, and strengthening postevaluation of research investments. Refinements in research planning and evaluation such as these will help strengthen the case for public support, improve the allocation of scarce research dollars, and help direct research programs into the most socially profitable areas.

A review of the biochemical and neuropharmacological actions of lithium

The pharmacological actions central to the therapeutic effects of lithium have not yet been established, despite almost 40 years of clinical use and scientific investigation. We review the biochemical and neuropharmacological data relating to this problem and attempt to identify profitable areas for further research.

The impact of scientific research on UK agricultural productivity

An attempt has been made to estimate the rate of return to agricultural research in the UK using an aggregate production function, in which research expenditure is related to changes in agricultural productivity. The average rate of return on research expenditure is estimated to have declined in real terms from 20–30 percent in 1966–1970 to 10–20 percent in 1976–1980. This compares with a required rate of return on investment in the nationalised industries of 5 percent and a projected real cost for public sector borrowing of 1 percent in 1975–1980. Projections for the period 1981–1990 suggest a further decline in the rate of return to 8–15 percent. The reasons for this decline may be threefold: (i) diminishing returns to research in toto, (ii) a failure to allocate resources to more profitable areas of research within the agricultural field, and (iii) a decrease in the efficiency with which research results are incorporated into new technology. However, in view of the considerable caveats surrounding the whole analysis, attempts to draw policy prescriptions must be treated with caution.

The Basis for Chinese Agricultural Growth in the 1980s and 1990s: A Comment on Document No. 1, 1984

Rather than considering the possible ramifications of each clause of Document No. 1, 1984 separately, this comment will focus on aspects of the document which are consistent with Chinese development strategy in the 1980s and those which acknowledge the principal vulnerabilities of the strategy as they pertain to agriculture. Much of the document is concerned with: (1) consolidating the gains achieved since the late 1970s in transforming rural organization via the production responsibility system and the attendant liberalization of rural markets; (2) extending the current areas of profitability in terms of increased production and the sale of farm goods that have become available through this transformation and especially in terms of reaping the rewards from specialization, hitherto untapped; and (3) more effectively setting the stage for future growth by attempting to generate confidence as to the durability of these organizational, and other critical policy changes.

The Role of Touch in Prey Density Estimation By Calidris Alba

We observed the performances and behaviour of Calidris alba while the birds searched in wet sand for the polychaete Nerine cirratulus by touch alone. The mechanism by which the birds determine the potentially most profitable area so quickly was investigated. The amount of tactile information sampled, was calculated to be far too small to have directed the search of C. alba, if it was assumed that the mechanoreceptors of the bill-tip organ function only, when they are in direct contact with prey. So, as the next logical step, touch perception of remote prey was introduced in the model and a minimal detection distance of 2 cm around the inserted bill tip was calculated. We inferred that remote perception of prey by touch is a common phenomenon in the Calidris genus and probably in some other wader genera too. Therefore, in addition to the definition of hunting types as formulated by Pienkowski (1981, 1982) a third category is proposed: The Plover type (visual), the Sandpiper type (remote touch) and the Oystercatcher type (direct touch). The eco-behavioural data provided us with constraints for the construction of the bill tip organ in a morphological sense by a quantification of the distance of detection.

Natural products of marine algae: the interface of chemistry and biology

Marine algae have a well deserved reputation as a source of interesting and diversified natural products, which present many challenges to the structural and synthetic organic chemist. While many classes of compounds are known, more notable groups are the sesquiterpeniods and diterpeniods and the fatty acid derived hydrocarbons, with halogenation being a frequent feature. The marine environment has long been known to biologists as a Pandora's Box of organismic interactions, especially between algae and herbivorous invertebrates. These interactions are well documented, frequently involving specific genera or families. Typical examples are toxicity or protection, chemoreception or chemosensing, site recognition, and communication. The molecular and cellular bases for these interactions are very poorly understood. In the last 10 years numerous investigations have implicated many of the odd natural products as the responsible agent. A full understanding of, and solutions to, these problems requires close collaboration between biologists and chemists. Biologists must provide careful observations of the phenomena and chemists must recognize isolate and characterize presumptive causative agents. Biologists must then test the chemists' hypotheses by carefully controlled field and laboratory experiments. A number of examples will be considered to illustrate these points. 1. (A) Genus specific (e.g., Plocamium, Laurencia, Dictyota, Lyngbya) herbivory exhibited by Opisthobranch molluscs (sea hares) e.g., Aplysia, Dolabella, Stylocheilus and the production of their defensive mechanisms. 2. (B) Larval settling and site recognition of algae by molluscs (e.g., Haliotis, Aplysia). 3. (C) Production of anti-predator toxins by algae (e.g., Caulerpa). 4. (D) Chemotactic substances produced by sexual gametes of brown algae (e.g., Ectocarpus, Fucus, Cutleria). There are other examples that might prove to be profitable areas of investigation. All will serve to emphasize that the ocean is more than just an oversized reaction flask producing exotic chemicals and that it is far more than just an assemblage of organisms waiting for a mathematical analysis. It is where biology and chemistry come together at the organismic level.

Multimarket Contact and Economic Performance

FOR the economy to work well, resources should flow freely from one industry to another in response to changing demands and costs. In textbooks, this process is via the capital market and entry and exit of firms. But entry can be by new firms or existing ones through diversification. Williamson (1970) and Weston (1970) stress advantages of internal capital transfers over the market.' Gort (1962, p. 4) and Rumelt (1974, p. 2) state multimarket operation of firms will speed redeployment of resources in response to profitable opportunities. They would be right if multimarket operation were not coincident with multimarket contact. While diversified companies may have advantages that would facilitate the movement of capital, they have enhanced opportunity for coordination if they meet in several markets. I term multimarket grouping the phenomenon of groups of diversified firms whose activities span to a significant extent the same markets. Multimarket grouping of sellers could reduce the flow of resources, thereby inhibiting a socially desirable competitive process, if it proceeded until mutual dependence among diversified sellers was recognized and reduction in competition coordinated, tacitly or otherwise. In short, where sellers have grown large through diversification, resources may not be efficiently reallocated among markets in response to changing conditions because interdependent groups of sellers recognize that reduces their profits. Even then, in a frictionless world, sellers other than those in the multimarket group could move resources into profitable areas. I reject such a frictionless world given evidence such as Mueller's (1977b) and the general theory of barriers to mobility (Caves and Porter, 1977). Those sellers having grown interdependent across markets are those who would have been most likely to enter given new profitable opportunities. Capacity expansion given such opportunities should be less rapid than if the multimarket interdependence did not exist. Is it in fact that just as with market concentration, not only the philosophy embodied in the Jeffersonian ideal, but economic efficiency provides grounds for concern about aggregate concentration when it coincides with multimarket grouping? This paper introduces methodology for measuring the significance of grouping and shows that when significant and coincident with high seller concentration, multimarket grouping does have economic implications. That coincidence, ceteris paribus, leads to higher profits. The question is whether those profits result from coordinated behavior or lower costs or both. The evidence suggests they are the result of economies of multimarket operation and barriers to the mobility of resources from outside the interdependent groups of sellers. Profits are lower for lines of business where multimarket contact is high but seller concentration is low, but higher when both contact and concentration are high than when concentration alone is high.

Spatial Variation in the Predation of Cockles by Oystercatchers at Traeth Melynog, Anglesey. II. the Pattern of Mortality

(1) The profitability (rate of biomass intake per bird) of each site to oystercatchers Haematopus ostralegus. depended not only on cockle Cerastoderma edule density but also on cockle size and flesh content. At very low cockle densities the individuals eaten were large, containing a lot of flesh (relative to their size), but the feeding rate was low. At high cockle densities many cockles were taken but they were small, containing little flesh. At a medium density of 25-150 cockles per m2 the profitability was at its maximum. (2) Oystercatchers fed most in areas of highest profitability (i.e. 25-150 cockles per m2) and so inflicted the highest cockle mortality in these areas. Over the period 1 December to 31 March, mortality was estimated at between 28% (at 45 cockles per m2) and almost zero (at 12 and 600 cockles per m2). (3) The actual disappearance of cockles was not clearly related to their density; however the downshore movement of cockles countered the effects of predation in the most profitable sites at the bottom of the shore. The large number of old cockles present accorded with the low mortality caused by the oystercatchers and the absence of cockle fishing.

Bioorganic modelling stereoselective reactions with chiral neutral ligand complexes as model systems for enzyme catalysis.

In terms of the reporting of accomplished chemistry this review can do no more than give an indication of the rapid progress in the branch of bioorganic modelling based on the use of macrocyclic compounds that (usually) act as complexing agents. What remains to be done, however, is to point out problems that have not been satisfactorily solved and to suggest other profitable areas of investigation. From the material accumulated in this review one can draw the conclusion that especially crown (or cryptate) systems offer special advantages in bioorganic modelling because such compounds can - enzyme like - complex a potential substrate. On the basis of quite simple binding considerations, coupled with an analysis of steric interactions, accurate predictions of the stereochemistry of the complex can be made. The inclusion of catalytic groups in the crown (or cryptate) system and reactive functional groups in the substrate is then done in such a fashion that the stereoelectronic arrangement is compatible with the predicted geometry of the complex. However, the good complexing ability of the ligand is paradoxically often its greatest failing in terms of developing a system in which the functionalized ligand acts truly as a catalyst. As seen from much of the chemistry discussed in this review the ligand is incapable of the double task of complexing substrate but releasing product in an enzymic fashion, i.e. that turnover occurs. How is this problem to be solved? Induced conformational changes are an obvious approach although the design of proper systems remains a challenge for which few suggestions outside of unlimited ingenuity can be given. Much of the solution to such problems will lie also in a much better understanding than we now have of non-covalent interactions and the stereochemistry of such interactions. The assembly and disassembly of large molecular aggregates by the making and dissolution of non-covalent bonds is an art at which chemists are still relative amateurs. A better understanding of non-covalent interactions may also provide the key to achieving also the twin goals of both speed and selectivity in bioorganic modelling. As far as enantioselectivity is concerned it is clear that this can be achieved fairly effectively by the use of relatively small, but appropriately placed, groups that force the substrate to complex in an enantioselective step with the ligand. In other words, the problem of enantioselectivity can be solved at the stage of complex forming, which is kinetically rapid. The p]roblem of rate enhancement lies in the mentarity with the transition state of the reaction being catalyzed. Again the achievement of this goal lies in ingenuity of design. Potential areas of applications of chiral crown ether (or cryptate) ligand systems in bioorganic modelling lie in, for example, the formation of carbon-carbon bonds, development of oxidative processes (i.e...

Coatings update: new proprietary products

New proprietary products continue to evolve. Many of them are water‐borne and are motivated by ecological considerations. Specialty products whose producers hope that their specialised nature will capture small but profitable areas of the market also continue to appear. Following is a review of some of the products that have evolved in the recent past.

The process of language comprehension; an approach to examining issues in cognition and language

The fundamental concerns of the field of cognitive psychology-understanding the nature of the mental representation of information and the processes which operate on those representations-have received their most extensive examination in the past decade in the field of psycholinguistics. The reasons for this are obvious: language is a relatively accessible domain for study, and the systematic classification and observation brought by linguistics and philosophy to language provided a major initial stepping stone for the investigation of the psychological functions underlying human language production and comprehension. And, while there has been much growth in a number of other fields in the area of cognition, the now-expanded domain of psycholinguistics still represents one of the most promising and profitable areas for examining cognitive function. It appears likely that major breakthroughs in understanding the extent of (and constraints on) our ability to perceive, process, store, recall and comprehend information will come from gaining a detailed empirical understanding of the nature of language processing. It is particularly important in this regard to underscore the point that language, like other cognitive functions, is a (dynamic) process. It is, in fact, precisely because it is a process that gaining an understanding of its nature has proved so intractable o4er the years; such an enterprise requires that we rely on more than just an examination of the end-state characteristics of the process (such as memory representations) or static models of its putative underlying structure. Rather, if we are to achieve any substantive understanding of language performance it is necessary that we examine the microstructure of the entire process as it occurs in real time. It is only through the careful examination of the temporal course of mental operations involved in the various levels of analysis underlying speech that we can hope to discover its nature. There are a number of critical questions underlying the examination of language as a process which must be answered in the coming years. The first, and in one sense most fundamental, concerns the basic nature of the integra-

Performance correlates in a postgraduate psychiatric examination.

This paper has reported some aspects of an analysis of the correlates of success in candidates' first attempts at the postgraduate psychiatric examinations of the R.A.N.Z.C.P. These are developed to suggest some attributes which selectors of trainees could take into account. Profitable future areas for research are delineated.

Pitfalls for Japanese Specialists in English Technical Writing

In order to correctly and concisely understand a scientific, technical English article written by Japanese specialists, the readers should understand in what areas of English grammar they are inclined to make mistakes when they write an English version. The most crucial mistakes made are usually certain aspects of English grammar. Learning the key mistakes from a Japanese specialist will also help an English teacher focus more efficiently on profitable areas of teaching.

Brain Carbohydrate Metabolism during Experimental Haemophilus influenzae meningitis

Five-day-old infant rats which acquire Haemophilus influenzae b bacteremia and meningitis after intranasal inoculation have a transient depression in weight gain (2 days), but then continue to grow at the same rate as strain U--11 inoculated controls. Brain lactate, glucose, and glycogen concentrations increase during the first 5 days of disease in infected animals. The increase in brain glycogen can be accounted for by an influx of glycogen containing polymorphonuclear leukocytes. The increased concentrations of glucose and lactate were found not to be due to a change in brain weight to dry weight ratio or the volume of entrapped blood. The mean cerebrospinal fluid (CSF) glucose concentration was higher in animals with meningitis (2.7 mM) in comparison to U-11 inoculated controls (1.8 mM). This increase in brain and CSF glucose concentration appeared secondary to an increased brain uptake of hexoses as manifested by an increased [3H]mannitol uptake. Brain lactate accumulation was not explicable from the data available. There was no evidence of cerebral cortical cellular damage because in vitro oxygen uptake and lactate production were equivalent in control and meningitic animals. The ability of the infant rat brain to maintain cerebral adenosine triphosphate (ATP) content in menigitis and the failure of CSF glucose concentration to decrease might be a reflection of the importance of alternative oxidative substrate (e.g., beta-hydroxybutyrate) to the cerebral metabolism of the developing rat brain.

Hunting Methods and Factors Affecting Their Use by Ferruginous Hawks

Recent theory suggests that a predator's foodsearching behavior should be predictable, given that the energetic costs and benefits of its foraging options are known (Emlen 1966, MacArthur and Pianka 1966, Schoener 1971, Rapport 1971, Pulliam 1974). Efficient foraging patterns should bestow a selective advantage upon the individual and, if heritable, eventually should become widespread within the population. Thus an animal should hunt in profitable areas and select an optimal diet. Similar predictions can be derived from learning theory which was extant in the psychological literature prior to the development by ecologists of optimal foraging theory. Drawing on earlier studies, Estes (1962) concluded that when confronted with two alternative tasks which offer different rates of re-

Electrical response of relaxing dielectrics compressed by shock waves: The axial-mode problem

Axial-mode conditions occur in studies of the dielectric properties of materials compressed by shock waves whenever the electrical vectors are perpendicular to a planar shock front. These conditions are readily obtained in shock experiments, and the analysis of the experiments is one dimensional. This work considers the electrical response of shock-wave-compressed dielectrics and piezoelectrics where changes in the polarization due to imposed electric fields do not occur instantaneously with field changes. Experiments are proposed in which the effective impedance shunting the specimen is either negligible or a series inductive-resistive network. These latter experiments are useful in discriminating between dielectric relaxation and other relaxation phenomena. Several example problems are solved, and they suggest profitable areas of future work.

The questionable immunogenicity of certain neoplasms

The possibilities of immunological intervention in neoplastic diseases are discussed in light of the accumulating findings that many spontaneously arising tumors of animals are not immunogenic in the host of origin or are not susceptible to immunological attack, and of the doubts as to the existence of tumor-associated antigens for many human neoplasms. Although some spontanous tumors do in fact display immunogenic properties and are subject to cytotoxic immune reactions, there are persuasive arguments for anticipating that a large proportion of naturally appearing malignant growths will be found to lack both immunogenicity and sensitivity to immunological effector mechanisms in the course of the host-tumor association. Even in the case of such tumors, however, significant opportunities for therapy and prophylaxis by extrinsic immunological manipulation remain cogent, as do eventualities of immunodiagnosis. These possibilities are discussed. It is concluded that whereas the simplistic assumptions which for some years set expectations in the field of tumor immunology must now be abandoned, reassessment of the nature of immunological parameters of host-tumor relationships and of the scope of immunological intervention on the basis of the information now available suggests that the immunological approach to the control of cancer continues to be a profitable area of investigation.

Ovenbird (Aves: Parulidae) hunting behavior in a patchy environment: an experimental study

We investigated the foraging behavior of ovenbirds (Seiurus aurocapillus) in a patchy food supply. Nine birds were individually exposed on 2 successive days to four patches of 1.5 × 1.5 m containing 2, 4, 8, and 16 prey, respectively, in a 6 × 6 m field arena. Patch locations were kept constant; however, prey densities were interchanged on day 2.Amount of search path in patches increased exponentially with prey density. Birds rapidly shifted their search effort when prey densities were interchanged. Differential distribution of search effort resulted from more visits and greater search path per visit, owing to greater tortuosity of the search path in denser patches. Since less search path was required per prey found in denser patches, the search effort was concentrated in areas of high profitability and the birds took a higher percentage of prey available in these patches. However, in comparison with a simple model, their foraging among patches was suboptimal, except in the final period of day 1. Birds tended to avoid some recently visited patches although the overall sequence of visits to the four patches was random.It is proposed that differences in renewal and depletion rates of prey are important determinants of foraging behavior of ovenbirds and other species feeding in patchy environments.

Plant Population Biology: An Overview

Population biology is a synthetic discipline that makes predictions regarding the adaptive behavior of plants through the formulation of models or hypotheses. Four main kinds of models in population biology are recognized: functional models, optimality models, growth models, and compartment models. Profitable areas for future research are indicated. Population biology is a synthetic discipline with the aim of understand- ing the mechanisms that govern the growth and reproduction of individuals and populations in order to be able to make predictions regarding future states under normal or abnormal environmental conditions. Its domain includes areas that until recently were considered to belong exclusively to the classical disciplines,of genetics, physiology, ecology, and systematics- such as gene frequency and its change in populations (genetics), energy harvesting and carbon allocation (physiology), interactions of individuals and populations in space and time (ecology), and characteristics of the life cycle (systematics). The final goal of population biology is to understand how an individual, a population, and a community function. According to Heslop-Harrison (1964) population biology makes the following propositions: 1) wide ranging species show variation over space in morphological and physiological characteristics; 2) much of this variation can be correlated with habitat differences; 3) much of this variation has a genetical basis; and consequently 4) that part of the variation that is corre- lated with habitat and that has a genetical basis is due to the action of natural selection in molding locally adapted populations from the pool of genetical variation available to the species as a whole.