Special Tendency Research Articles

Specialization versus diversification in venture capital investing

PurposeModern portfolio theory demonstrates that a well‐diversified portfolio will minimize unsystematic risk. It may be impractical to achieve a well‐diversified portfolio of venture capital (VC) investments due to market imperfections, leading to the decision to specialize. The purpose of this paper is to determine the implications of choosing a strategy of specialization versus diversification in venture investing.Design/methodology/approachUsing a dataset of US VC funds across a 20‐year time period, this paper verifies that there has been a tendency for venture capitalists to pursue a specialization strategy in both industry and stage of development of portfolio firms. A multivariate two‐limit tobit model is constructed to determine the effects of these decisions on venture success rates.FindingsIt is found that venture capitalists that diversify across portfolio company stage of development have greater success in bringing companies public and exiting their investments via acquisition. Industry specialization has no significant impact on venture fund success rates.Research limitations/implicationsSuccess rates may be less important than returns to investors in VC. Future research should examine the effects of specialization on investor returns.Practical implicationsIt may be beneficial to increase the level of diversification of VC investments across portfolio company stage of development. The lack of diversification across industry has not significantly affected success rates across funds, thus the tendency to specialize in particular industries over the sample period is not necessarily a poor decision.Originality/valuePrior research demonstrates a tendency for specialization in VC investing. This paper examines the implications of adopting this strategy.

Local genetic structure in a North American epiphytic lichen, Ramalina menziesii (Ramalinaceae)

Epiphytic lichens possess unique life history traits that can have conflicting effects on genetic structure: symbiotic mutualism between a fungus with its algal or cyanobacterial photobiont, association with a host plant, and ability to reproduce sexually and asexually. Our study species, Ramalina menziesii, has small ascospores that can facilitate long-distance gene movement, and it is capable of clonal reproduction. The goals of this study are to test whether different haplotypes were differentially distributed across host plant species, to look for evidence of asexual vs. sexual reproduction, and to assess the local genetic structure of the population. We sampled individuals from multiple trees of three oak species in four lichen subpopulations within a savanna ecosystem. Using DNA sequence data from four fungal nuclear loci, we found no tendency for host specialization. Alleles were randomly distributed across subpopulations. The frequency of multilocus genotypes was consistent with a randomly mating population. Sexual reproduction involving relichenization appeared to be the predominant mode of reproduction of R. menziesii at this study site. We found no significant local genetic structure suggesting widespread gene flow at the local scale. The genetic structure of this lichen is comparable to that of widely distributed epiphytic plants.

Histology of the primary tumor and subsequent metastasis in breast cancer

The relationship between the histology of the primary tumour and subsequent metastasization was analysed in 343 patients with disseminated carcinoma of the breast. The metastases were subdivided on clinical criteria into osseous, visceral and localized regional ones. It was found that undifferentiated, infiltrating ductal carcinomas without significant productive fibrosis have a special tendency towards visceral metastasization. Purely scirrhous carcinomas, especially without intraductal components, have a marked affinity to the skeletal systems. Intraductally growing and adenomatous carcinomas appear to metastasize ubiquitously. The more components there are to the primary tumour the more frequent are local recurrences and metastases to several organ systems.

Sources of variation in firm profitability and growth

This article reports an analysis of the sources of variation in profitability and growth for manufacturing firms located in eleven European countries. A variance decomposition analysis determines the importance of the country, industry, corporate group and firm effects on profitability and growth. The analysis reveals evidence of differences between industries in the comparative advantage offered by different countries, reflecting a tendency for specialization and geographic concentration. However, as in several previous studies, the firm-level effects are the most important class of effect in explaining the variation in performance.

Vitamin A rewrites the ABCs of oral tolerance

One of the chief requirements of an immune system, the mucosal immune system, that lies juxtaposed to a mass of potentially immunogenic commensal organisms is a well-developed mechanism to limit or negatively regulate nascent immune responses to those organisms. This mechanism, long subsumed under the name oral tolerance, is now understood to consist of a complex of factors, not the least of which is the ready ability to induce immunosuppressive regulatory T cells or Tregs. The emphasis here is on the “ability to induce” because the real individuality of the mucosal regulatory response lies not in the Tregs themselves, which after all can be induced anywhere and are mere tools of regulatory response. Now, as shown initially by the fact that oral tolerance is dependent on the size and mobility of its dendritic cell (DC) population, the individuality of the mucosal immune system is inherent in its inducing cells, i.e., the antigen-presenting DCs (or macrophages) of the mucosal immune system.1, 2Recently, new data have emerged that provide much more specific information on how mucosal DCs (or macrophages) are different in this respect and thus why they have a special tendency to facilitate the development of Tregs that then mediate oral tolerance. This is the subject of this brief review. The unresponsiveness of mucosal immune system to mucosal antigens is due to a process known as oral tolerance. Recent studies addressing the mechanism of such tolerance show that mucosal tissues are replete with a unique subset of dendritic cells that secrete factors such as, TGF-β1 and retinoic acid, that induce foxp3+ regulatory T cells. Thus, we arrive at the somewhat surprising realization that mucosal unresponsiveness is, appropriately enough, related to the availability of a factor in the food stream.

Inter and multidisciplinarity in engineering education

After reviewing the concepts of trans, inter and multidisciplinarity, the paper discusses the relevance of inter and multidisciplinary approaches to engineering education at undergraduate level, specially taking into account the continuing tendency for specialization of engineering degree curricula. This tendency is substantiated by a detailed analysis of the evolution in the last 30 years of the Mechanical Engineering degree syllabus at Faculdade de Engenharia da Universidade do Porto (FEUP). A 2-year multidisciplinary project developed at FEUP is presented as a case study. This project involved students and faculty from five Departments of FEUP, as well as from other institutions, in the joint exploration of practical engineering problems.

Fístula aorto pulmonar: endocarditis izquierda en paciente VIH y ADVP: Revisión de la literatura

Infective endocarditis (IE) is the most severe complication in intravenous drug abusers (IVDAs). HIV infection increases the risk of IE in IVDAs too. IE in both population are special tendency to infect the right-sided heart, but unusual infective aortic valve. We report a case of HIV and IVDA patient admitted in hospital due to fever syndrome, with X-ray test normal and the first blood cultures negatives. CD4 count cell 90 mm3. It was impossible doing a transesophageal echocardiography (TEE) and transtoracic echocardiogramma (TTE) only showed a moderate aortic insufficiency with conserved systolic function. Despite using antibiotics, antifungals and highly active antiretroviral therapy, he developed ARDS, and mechanical ventilation should be performed. At that moment, TEE showed an aorto pulmonary fistula due to left-sided IE. Further cultures was undergone and only one blood culture was positive to Staphylococcus aureus. Cardiac surgery was not indicated. The patient died 3 weeks later.

Sports Celebrity and the Civilizing Process

One of the most important concepts in the figurational/process sociological approach is also one of the most under-examined: functional democratization. This refers to the tendency of functional specialization and the division of labour to diminish imbalances in the power balance between groups. The essay discusses the concept and, drawing on Emile Durkheim's concept of ‘egoism’, argues that the rise of celebrity culture provides an important challenge for the concept. The Sports Star is now the object of intense emotional attachment from fans. This exceeds an attachment based upon appreciation of sporting prowess. The leading Sports Stars, in common with the leading celebrities from celebrity culture, are adopted as role models by fans and their lives are followed as parables of normative behaviour. A new term, invasive egoism, is introduced to describe the development of fantasy relationships between the fan and the sports star. Invasive egoism can produce over-close identification between fans and their idols, so that the media representations of the star's life become the fulcrum for measuring changes and moments of significance in the life of the fan. The rise of the Sports Star is related to the onslaught of the commodification of sports culture.

Insulin signaling and limb-patterning: candidate pathways for the origin and evolutionary diversification of beetle ‘horns’

Beetle 'horns' are rigid outgrowths of the insect cuticle used as weapons in contests for access to mates. Relative to their body size, beetle horns can be enormous. They protrude from any of five different regions of the head or thorax; they are curved, straight, branched or bladed; and their development is often coupled with the nutrient environment (male dimorphism) or with sex (sexual dimorphism). Here, we show that this extraordinary diversity of horns can be distilled down to four trajectories of morphological change--horn location, shape, allometry and dimorphism--and we illustrate how the developmental mechanisms regulating horn growth could generate each of these types of horn evolution. Specifically, we review two developmental pathways known to regulate growth of morphological structures in Drosophila and other insects: a limb-patterning pathway that specifies the location and shape of a structure, and the insulin pathway, which modulates trait growth in response to larval nutrition. We summarize preliminary evidence indicating that these pathways are associated with the development of beetle horns, and we show how subtle changes in the relative activities of these two pathways would be sufficient to generate most of the extant diversity of horn forms. Our objective is to intuitively connect genotype with phenotype, and to advocate an informed 'candidate gene' approach to studies of the developmental basis of evolution. We end by using this insight from development to offer a solution to the long-standing mystery of the scarabs: the observation by Darwin, Lameere, Arrow and others that this one family of beetles appeared to have a 'special tendency' towards the evolution of horns.

Pseudomonas aeruginosa under Phosphorus-Poor Culture Conditions: Phospholipid-Poor Bacterial Membranes, and Susceptibility to Antibacterial Chemicals, High Temperature and Low pH.

Pseudomonas aeruginosa, Pseudomonas fluorescens, and Burkholderia cepacia were able to grow in a phosphorus-poor (0.01 mM of phosphate) synthetic medium in chemostat cultures. In contrast to bacteria grown in a phosphorus-rich (10 mM of phosphate) chemostat, they underwent an extensive changes in lipid composition, with phospholipids being replaced with ornithine-containing lipids. Nevertheless, their susceptibility to twelve antibiotics, and seven germicides changed little. No special tendencies in drug susceptibility related to the replacement of membrane lipids were recognized. Thus, though growing in a phosphorus-poor environment, these bacteria did not exhibit any special resistance to antibacterial agents. With regard to susceptibility to low pH, P. aeruginosa grown under phosphorus-poor conditions demonstrated greater resistance.

The structure and function of folliculo-stellate cells in the anterior pituitary gland.

The folliculo-stellate cells (FS cells) in the anterior pituitary gland are characterized by their star-like appearance and their ability to form follicles. Although FS cells do not produce any pituitary hormones, their special tendency to surrounding endocrine cells with their long cytoplasmic processes suggests that they regulate endocrine cells by intercellular communication. In spite of many morphological and cytophysiological studies recently performed, a precise understanding of the major functions of FS cells in the pituitary gland remains obscure. We review here the morphological characteristics of FS cells and their suspected functions in the anterior pituitary gland. It is well established that the FS cell produces many kinds of growth factors, i.e., fibroblast growth factor, vascular endothelial cell growth factor and interleukin 6. The biological significances of these growth factors in the anterior pituitary gland are also discussed in this paper. The origin and differentiation of FS cells, especially the possibility that the FS cell is a kind of stem cell which has the potential to differentiate into endocrine cells, is also presented.

Direct and diffuse photosynthetically active radiation: measurements and modelling

Knowledge of photosynthetically active radiation is necessary in different applications dealing with plant physiology, biomass production and natural illumination in greenhouses. Nevertheless, due to the absence of widespread measurements of this radiometric flux it is often calculated as a constant ratio of broadband solar radiation. This ratio is affected by many parameters. In our previous work, we analysed the global horizontal component of this flux. This work describes the variations of the direct and diffuse ratios of photosynthetically active radiation to broadband solar radiation in sky conditions. The latter has been characterised by means of variables that could be accessible in common radiometric networks. For this purpose, data recorded at two radiometric stations are used. The first one is located at the University of Almerı́a, a seashore location (36.83°N, 2.41°W), while the second one is located at Granada (37.18°N, 3.58°W, 660 m a.m.s.l.), an inland location. The database includes hourly values of the relevant variables that cover the years 1993–1994 in Almerı́a and 1994–1995 in Granada. We have studied the variability of the ratios of photosynthetically active radiation to broadband solar radiation, both for the diffuse and direct components. We have explained this variability through the influence of sky conditions, represented by means of broadband solar radiation dimensionless ratios, solar zenith angle and dewpoint temperature. Additionally we have developed weather dependent functions of this ratio, to obtain an empirical model, which could be applied to estimate the photosynthetically active radiation in those radiometric networks that register solar broadband irradiance. The model validation shows that all the models estimate the experimental values with mean bias deviation (MBD), close to 1–2%. On the other hand the root mean square deviation (RMSD), presents values close to the experimental error. The regression analysis of measured versus estimated values of direct and diffuse photosynthetically active photon flux density, Q pb and Q pd, indicates the absence of given ranges with special tendencies to over or underestimate the fluxes. The use of data sets from two different climatic conditions enables the verification of the local independence of the proposed technique.

Expression of sterol carrier protein 2 (SCP2) in human adrenocortical tissue

Sterol carrier protein 2 (SCP2) has been implicated in adrenal steroidogenesis by in vitro studies. In order to clarify the clinical significance of SCP2 in human steroidogenesis, we investigated the expression of SCP2 mRNA in various types of adrenocortical tissue and one testis and examined the correlation between the amounts of SCP2 and other values such as the free cholesterol content and the cholesterol side-chain cleavage (SCC) activity in the tissue mitochondria. The types of adrenocortical tissue examined included adrenocortical carcinomas (N = 3), adrenocortical adenomas from patients with Conn's syndrome (N = 3) and from patients with Cushing's syndrome (N = 3), non-functioning adrenocortical adenomas (N = 2) and normal adrenal glands (N = 2). Northern blot hybridization predominantly revealed a 1.8-kb SCP2 mRNA in all tissue specimens examined. The mRNA concentrations of SCP2 in two out of three adrenocortical carcinomas were relatively lower than those in other types of tissue. No other special tendency was observed regarding the mRNA expression levels in various tissue specimens. The mRNA concentrations of SCP2 correlated significantly with mitochondrial contents of free cholesterol (r = 0.67, p < 0.01), but was not correlated with the SCC activities in mitochondria measured by an in vitro enzyme assay. The mitochondrial SCC activities, however, were correlated significantly with the protein levels of mitochondrial P-450 scc determined by a Western blot analysis (r = 0.79, p < 0.01). The significant positive correlation between mRNA concentrations of SCP2 and the mitochondrial content of free cholesterol suggests that the central role of SCP2 in human steroidogenic tissues may be in part a translocation of cytoplasmic free cholesterol to the mitochondria, as demonstrated previously by in vitro studies.

Why does the frontalis muscle "never come back"? Functional organization of the mimic musculature.

The normal function of the forehead muscle after severe damage to the facial nerve, and especially after nerve reconstruction in the trunk region, cannot be regained. This striking phenomenon was described as early as in 1936 by Martin and in 1948 by Tickle [1,5]. Miehlke (1973), in his classical monograph [2] on the “Surgery of the Facial Nerve” summarized this fact as follows: “Every expert in the surgery of the facial nerve knows about the repeatedly mentioned experience that, after a lesion of the facial nerve, recovery of the frontal part of the occipito-frontal muscle is either incomplete or non-existent. This is almost the rule after neurotmesis… The peculiar behavior of this muscle is not yet explained”, and he continued: “One might be permitted to think that the frontal part of the occipito-frontal muscle has some special tendency toward atrophy and fibrosis” (p. 239).

Gender Differences in Achievement Motive: A Facet Analysis of Hungarian Samples

We devised an achievement motive questionnaire (Elizur 1979, 1986; Shye 1978a) based on a facet definition of achievement motive. We then administered it to 165 women and 362 men employed by a large industrial corporation in Hungary in order to examine achievement motivation. Although we found significant differences in the frequency of responses to the achievement motive items, the basic structure of the achievement motive domain was similar for women and men. We detected no special tendency for women to score higher than men on affective responses. These results support the view that gender differences in achievement motive are rooted in socialization processes rather than in basic differences between women and men.

The aggregation of colloidal particles at the air—water interface

Previous investigators have noted that small particles at a fluid interface may exhibit a special tendency to aggregate. Colloidal dispersions which are stable in the bulk often form a coagulum at the air—liquid surface. Such surface aggregation is an important factor in operations that require clean or controlled interfaces. The present work seeks to describe particle adsorption and aggregation at the air—water interface in quiescent systems. A model is proposed for two-dimensional rapid aggregation as well as for slow surface aggregation dependent upon modified van der Waals and electrostatic interactions between particles at the surface. Experimental results from direct observation by darkfield microscopy of particle adsorption and surface aggregation are reported and found to be in qualitative agreement with the model predictions.

Economic evolution and specialization

AbstractAs an economic system grows and develops, several key processes occur. Growth means greater population and larger markets, allowing the economy to diversify. Economic development leads to improvements in infrastructure, including transportation networks, which facilitate trade and encourage specialization.In this paper we examine the effects of economic evolution on the structure of 22 national economies, with particular emphasis on their levels of industrial diversification, and how this process affects the international economic system.Our results show a clear tendency for a nation's specialization to decrease over time as development occurs, but only up to a point. The degree of specialization falls more slowly over time in virtually every case, with specialization tending to increase again in several of the most developed economies. Greater specialization means greater interdependence; increasingly, a change in a distant economy has effects in seemingly unrelated places due to these interconnections. A key consequence of this is an increasing need to take a systems approach in economic analysis.

The function of friends in preschoolers' lives: at the entrance to the classroom

The function of friendships and peer attachment in preschoolers' everyday lives is examined from the ethological view point. It is postulated that a child invests time and energy in friends or play partners chosen by him/herself: the child collects information about the friends and attempts to influence their special behavioural tendencies to his/her own advantage. As a result of this long-term investment, the friends are more predictable, controllable, and cooperative. It is hypothesized that a child uses and benefits from the friends in attempts to reach his/her personal goals. This study examines whether a child benefits from friends in attempts to join in play. Seventeen German preschool children (10 boys and 7 girls) ranging in age from 36 to 79 months were observed on arrival at school on 18 preschool days. When friends were present in the classroom, children first approached peers more often than when friends were not present; otherwise they approached the teacher. Friends often actively initiated interaction with arriving children, for example by calling the child's name. Success in joining in play was highest when friends were chosen as the target of the approach. During approaches to friends, tactics were more frequently used which require specific information about the target. However, when friends were playing with nonfriends of the children, benefits such as initiation by the target and the larger range of alternatives in strategies were not observed. The results support the hypothesis that a child uses and benefits from friends. The results further suggest that the relationships of friends with other peers disturb the beneficial effects of friends and that such relationships even increases the costs in interactions with friends.

A case study of risk-return tradeoffs in a mixed farming system in highland Ethiopia

The role of livestock enterprises as a risk management option for subsistence smallholder farmers in an Ethiopian highland site (Debre Berhan) is examined. Specifically, the paper addresses the issue of whether livestock enterprises can be an income stabilizing agent in a traditional mixed crop and livestock farming system representative of important parts of the Ethiopian highlands. The analysis is based on the application of a stochastic farm-firm linear programming model. Farm income is the stochastic variable of the model. Technological and resource constraint sets which approximate those of representative smallholders in the Debre Berhan area are incorporated into the empirical framework. The data inputs to the model have been collected in field surveys conducted by ILCA (International Livestock Centre for Africa) covering the period 1979–1983. Linear programming solutions are obtained for three situations: 1. (1) A set of solutions where traditional farm technologies apply. 2. (2) A set of solutions where farmers can use one ox, rather than the traditional pair, for cultivation. 3. (3) A set of solutions where farmers can keep a relatively high-yielding crossbred cow for milk production to raise cash incomes. The main empirical results are: 1. (1) In the traditional farming system, increasing sheep flock sizes reduces income variation. 2. (2) The single ox-traction technology offsets income variation by increasing mean income as a result of its higher efficiency as compared to the oxen-pair traction technology. 3. (3) The adoption of the crossbred technology results in a lower income coefficient of variation. This is mainly due to its high mean income. However, due to the labour-intensive nature of the crossbred cow enterprise, labour becomes expensive. As a result, a tendency for crop specialization arises.

The role of the therapist in cases of child neglect/maltreatment, with a special focus on foster placement

Abstract In cases where the child has been removed from its own home and is placed in a foster home because of abuse and/or neglect, the children often have serious psychological disturbances. It is essential that an exact evaluation be undertaken. This includes psycho-diagnoses where the child's past is evaluated as well as its present functioning. In a new relationship one must expect that the child will regress emotionally, and make a new start from the very point where it stopped being cared for, or where traumas intruded upon its life. We can expect a new attachment process in relation to a new object At the same time we must be prepared for another type of process running parallel to and alternative with the above-mentioned: the transference process The children we speak of here will often have a special tendency to project unbearable self-aspects into the other person especially the person to whom the child is most attached -e.g. a foster parent. The transference/countertransference process thus put into motion may create vicious circles eventually leading to a breakdown. The child also faces loyalty conflicts concerning biological parents/ foster parents. It is essential for the child and the foster parents to get professional help from a child therapist in these difficult fields. A case is presented illustrating these points.